07:46 Good morning and welcome to the first AUTOSPORT Live commentary of the 2014 Formula 1 season, as pre-season testing kicks off at Jerez.

07:47 Of course, all the focus this morning has been on the appearance of this year's designs as Mercedes, Red Bull, Force India and Williams all rolled out in the pitlane ahead of the start of the test.

You can check out AUTOSPORT's gallery of every design so far here.

07:47 The sweeping rule changes will also have a massive impact on what teams are hoping to achieve on this first day of testing.

Last year, for example, Paul di Resta completed 89 laps on Force India's opening day.

AUTOSPORT's technical guru Gary Anderson reckons hitting a quarter of that tally today will represent an impressive start.

07:47 It will also be fascinating to see what times the cars are capable of, and how spread out the field will be – even if the usual disclaimers about this being the first day are more pertinent than ever.

As a reference, Jenson Button set the pace last year with a 1m18.861s, with all 11 runners covered by 5.315s.

07:51 We're 10 minutes away from the start of F1 2014, and all the unknowns that surround one of the biggest rule changes in the sport's recent history.

Which is as good a time as any to remind you that we'll be bringing you live updates across the four days at Jerez, covering every lap of on-track action and all the latest news and gossip from the paddock.

07:54 The first engines fire up down in pitlane.

Curious to know what they'll sound like at full chat? Our man KEVIN TURNER is down at Dry Sac, and will be bringing you the low down on what the new era of F1 sounds like later today.

07:57 Into the final five minutes, which is the perfect time to recap today's driver line-up:

Reigning champion Sebastian Vettel will take over duties for Red Bull, accompanied by Lewis Hamilton (Mercedes), Kimi Raikkonen (Ferrari), Jenson Button (McLaren), Sergio Perez (Force India), Esteban Gutierrez (Sauber), Jean-Eric Vergne (Toro Rosso), Valtteri Bottas (Williams), Max Chilton (Marussia) and Marcus Ericsson (Caterham).

Phew.

08:00 Lewis Hamilton has the honour of being the first man to take to the track in the Mercedes. F1 2014 is officially underway.

08:03 The Mercedes, incidentally, is for our money the best looking car we've seen so far.

Do you agree? Head to our Facebook page to have your say on this year's designs - and of course the controversial protrusions some teams are sporting.

08:05 Hamilton straight back in after a slow exploratory lap, which featured the unusual timbre of a turbo at low speed and pressure.

08:10 After Hamilton's lap, the track falls silent. Mercedes, remember, shook its W05 down at Silverstone last week with Nico Rosberg - under the tag of a promotional day.

Toro Rosso (Misano) and Force India (Silverstone) have also given thir cars brief run-outs before today.

08:16 Teams have been keen to stress just how difficult this opening day of testing is likely to be given the huge number of new processes, designs and layouts they have had to process.

As James Key, technical director at Toro Rosso explains:

"I think we will get a lot of red flags this week. There are a lot of unknowns and there is going to be stuff that completely catches you out of the blue.

"This week, for us, isn't a performance week, it's a reliability week.

"We have got this opportunity now to learn the management of the power unit, learn how well we manage it with the chassis, while the drivers can get a feel for how the car is behaving. We then have the gap to the Bahrain test where we can address a lot of that stuff."

08:18 All of which means it might be a while before we see anyone do more than the preliminary installation lap Hamilton managed first thing this morning.

08:20 EDD STRAW, our scout in the pitlane this morning, reports that the Mercedes fired up again and rolled halfway out of the garage, only for its engine to stop. The W05 was promptly wheeled back in and hidden behind screens.

08:21 @danielricciardo: "Car looks like a hot rod! It's got swag. Pumped!"

08:27 What do you think of Red Bull's new RB10?

The team has at least attempted to mask its protruding nose design, as the photo to the right shows.

Join the debate about this year's designs on our Facebook page.

08:29 If you're not a fan, you're not alone. Here's Toro Rosso team boss Franz Tost on this year's creations.

"I don't like these noses, to be honest. I think that this is not F1-like.

"This is how the engineers have found the best solution from the aerodynamic point of view, but I don't think that these noses should have a big future."

Read the full story here.

08:31 Caterham was due to unveil its 2014 challenger at 0845 this morning, but was delayed by a small glitch that AUTOSPORT understands is related to the installation of the engine.

There has been no further word on when it will roll the car out.

08:33 We have track action, as Hamilton heads back out for Mercedes.

The good news is that fears about the noise of the new-era V6 engines seem unfounded - the car sounds beautiful as Hamilton guides the W05 through the first few turns and onto the back straight.

He's headed straight down to our man KEVIN TURNER, who is at Dry Sac for a first exclusive look at how these cars sound and move on track. Look out for that later (we'll need a few more cars out first).

08:35 Straight back into the pits for Hamilton, who was posing earlier as team-mate Nico Rosberg played photographer at the team's pitlane launch.

08:38 There's a distinctive rumble from directly beneath us in the media centre, which means one thing - Ferrari has fired up its F14 T.

08:39 And out heads Kimi Raikkonen for the Scuderia, which is sporting a massive pitot sensor on the top roll hoop.

08:42 One man not running at this test, of course, is Lotus's Romain Grosjean.

The Frenchman's team is the only squad officially missing the entire four days, but he's still paying close attention to events.

@RGrosjean: "Watching pictures from Jerez ! Always exciting to discover new cars, new helmet designs ! #f1 #2014"

08:47 We have our first red of the day.

Raikkonen has stopped entering onto the back straight.

08:49 Ferrari mechanics hop into a course car and head down to the F14 T, which is parked just after the Curva Sito Pons. Our man KEVIN TURNER, sat at the end of the back straight, has a perfect view.

08:50 An update on Williams's situation:

@WilliamsF1Team: "For those waiting to see the #FW36 you will have to wait a short while longer but I promise you we'll have her on track as soon as we can!"

08:51 Raikkonen returns in a SEAT recovery vehicle. The F14 T is still out on track though.

08:52 Red Bull design genius Adrian Newey is addressing the media later this morning. He's already had a brief say on the 2014 technical regs, and it's fair to say he's not best pleased with the aerodynamic rules.

While, in the case of the front wing, that's because of performance implications - "the narrower wing means the endplate is in the worst possible place in front of the wheel" - he's in agreement with the majority of fans over the look of the new noses.

"They are ugly and ungainly," he said. "To me the aesthetics of a Formula 1 car are important.

"The car should look good, and not many owners of these noses could say they really love them."

08:59 How did F1 get itself into this position with the nose rules?

AUTOSPORT tech expert CRAIG SCARBOROUGH's in-depth series on the 2014 technical revolution explains how a relatively minor regulation aero regulation tweak led teams down this path:

F1 2014 tech insight: The aero controversy

09:02 Ferrari don't seem to be rushing the retrieval.

KEVIN TURNER says the mechanics aren't too animated as they weigh up moving the car onto the low loader.

09:03 Ferrari says the stop was precautionary:

@InsideFerrari: "#F14T out but not in. Precautionary stop by engineers, now checking. Car on its way back to the pits..."

09:06 Raikkonen's F14 T heads back on the low loader, as the FIA's safety vehicle heads back to position at the exit of the pitlane.

A media scrum, predictably, has gathered outside Ferrari's garage as the car returns.

09:07 The car is hidden by a sheet, and the team has wheeled boards out.

The only issue is the media ensemble is too large for them to cover every angle, so expect plenty of images and footage in the next few minutes.

09:08 After a lengthy delay, the track is open once again.

09:09 An update from Marussia:

@Marussia_F1Team: "Very pleased to report that the #MR03 is now on its way to #Jerez. Well done Team for resolving the issue. Our garage awaits you!"

09:11 AUTOSPORT learned last night that the team had delayed its 2014 test debut because of a last-minute technical glitch, and had kept its car in the UK in order to work on the problem.

Read the full story here

09:15 More than one hour in to this first day, and we haven't exactly had a wealth of running to talk about.

Only two men - Lewis Hamilton and Kimi Raikkonen - have headed out, and neither has completed a full lap.

Hamilton does at least have two installation laps under his belt. Raikkonen by contrast got as far as Turn 5, Curva Sito Pons, before pulling his Ferrari to a precautionary halt.

09:17 That state of affairs shouldn't be seen as worrying though, according to our technical guru GARY ANDERSON:

"It's no surprise to see the teams not up and running because every time you open the garage and fire up the car you will find something else you need to attend to.

"These cars with all the complex systems, wiring and cooling requirements are a nightmare in the early stages.

"This is what today is going to be about - getting the car out when you can, troubleshooting problems and encountering these initial breakdowns with the new technologies.

"Everything is electronically controlled but before you can write defaults into software that will react to problems. This was inevitable, so I wouldn't get too concerned about teams having problems today.

"They will be overcome. F1 cars last year were very complicated, but these are probably 10 times more complicated so there is a huge amount to learn."

09:19 An engine fires up in the pitlane - and it's Lewis Hamilton in the Mercedes, heading out for a third lap.

09:21 More news on Marussia's delayed debut here:

Delayed Marussia heads for Jerez test

09:22 Force India, which has run before Jerez in a promotional day at Silverstone, is still working on its VJM07.

@clubforce: "Still quiet on the track here in Jerez. Our crew preparing the car for our first run of the day #FeelTheForce"

09:23 Hamilton goes purple in sectors one and two, but that's not exactly difficult right now. He's straight back into the pits, his lap count of three still three more than anyone else.

09:28 Mercedes has a new hashtag, for today at least...

@MercedesAMGF1: "Well, well... who's this then? Back to business for @LewisHamilton #W05sup"

09:33 Another man playing down the significance of early impressions is Renault engine chief Rob White, who argues the lack of running shows just how complicated integrating the new chassis and power units is.

"It is clear that the objectives for testing are to go through all the scenarios that are necessary to establish the basic functioning of the car," said White, whose engines will power Red Bull, Toro Rosso and Caterham this year.

"We would like to run lots of kilometres and the most recent activities at the factory have been to prepare all the necessary steps in order to do that.

"We are setting out our stall to run the car, not to spend the week in the garage. But it is extremely important to appreciate how much newness there is with these cars, and how much newness there is with these power units.

"The list of things to do is immense and we are not at the level of maturity we would be at this time of year normally, but that is kind of understood and expected."

09:36 In the quiet, how about a shot of the Ferrari crew gathering around the low loader carrying Kimi Raikkonen's stricken F14 T?

If you missed it earlier (see 0847), the Finn completed just five corners before pulling to a precautionary stop entering on to the back straight.

09:39 Further updates from Caterham, which was due to unveil its 2014 car this morning but had to postpone its reveal due to a glitch (see 0831).

@CaterhamF1: "Work continues in the garage to prepare for our first run of 2014. We still can't say when that'll be but we're definitely aiming for today!

"Meanwhile... our nightshift crew have just been sent back to the hotel to grab some well deserved sleep while the dayshift continue the work.

"We do have a few people here who haven't slept since early yesterday... it's not just the cars that pre-season tests...."

09:41 KEVIN TURNER's trackside assessment of a relaxed Ferrari crew was spot on:

@InsideFerrari: "No one attempted pit exit, only #Ferrari and Merc. New systems check long and complex process, #verycalmTeam nonetheless"

09:43 We're on maths duty in the media centre...we've established, through complex algorithms, that we're currently on around two laps per hour at Jerez.

09:45 We've also crunched last year's data. Day one's 2013 tally? 637.

09:46 Aha. An engine (the sound is already starting to grow on us).

It's from the far end of the pitlane, which means the guessing game lottery starts. We're playing the percentages though and saying Mercedes...

09:49 It is indeed Mercedes, as Hamilton heads out for a fourth run in the W05. It's as brief as the previous three though, and he's straight back in.

09:50 We have a third car to try a lap - Jean-Eric Vergne heads out (very gingerly) in the Toro Rosso.

09:53 Vergne is straight back in, but we now have six laps (counting the Ferrari's aborted attempted) on the board.

09:59 While we're waiting patiently in the media centre for any sign of further action, JONATHAN NOBLE is discussing everything 2014 with Red Bull's design guru Adrian Newey.

We'll be bringing you all the latest interviews, rumours and paddock gossip across the four days at Jerez.

10:00 Meantime, we have another engine - and another new car! New Force India recruit Sergio Perez heads out in the VJM07.

10:01 Which is the perfect time to bring you a round-up of the first two hours (disclaimer: this won't take long).

No driver has set a single timed lap, but we've now had four head out on single-lap runs.

Leading the way is Hamilton, who has clocked up four laps for Mercedes. Vergne has completed one for Toro Rosso, while Raikkonen stopped out on track on his first run.

10:02 Perez won't complete that lap though - he's stopped out on circuit, and we're back to reds.

10:02 Force India unveiled the VJM07 two hours ago. It's fair to say its nose has been one of the most attention-grabbing of an already controversial bunch:

Force India launches the VJM07

Compare it to the rest of the field in our gallery:

2014 F1 designs so far

10:05 Our man at the trackside KEVIN TURNER just watched the Force India grind to a halt in front of him at Dry Sac.

Just before it did so, he managed to snap this picture of it moving. And we assume that's a portaloo in the frame as well.

10:09 Sauber had just been building up to its first run of the day before that stoppage:

@OfficialSF1Team: "#Guti is in the car cranking the engine in preparation for the first outing of the #C33 #Jerez"

10:11 Swift response as ever by the pitcrew - a selection of Force India's team jumps into a course car and races off to the VJM07, which has stopped, as Raikkonen did, on the back part of the circuit.

10:14 Speaking of Gutierrez, the young Mexican admits adjusting to driving in F1 2014 will require massive effort:

"To adjust to a new car this year is pretty special because the regulations are quite a dramatic change.

"There's a difference in strategy, a difference in the way to drive the car and this will take a lot of time and analysis.

"Testing is going to be pretty important for this because obviously we want to go to the first race fully prepared and 100 per cent adapted to our package."

10:16 Gutierrez is back, and no sooner does the track go green than Hamilton fires up the W05 and heads back out for his fifth run of the day.

10:19 Hamilton is very vaguely leaning on the car here - and he's onto his first flyer!

He hits 260km/h down the main straight as he begins that sixth lap.

10:19 From the first flyer, we now have two cars on track for the first time, as Gutierrez heads out for Sauber.

10:20 Make that three, as Vergne heads out for Toro Rosso.

10:20 Hamilton's first flyer - and the first of the day - is a 1m33.305s.

10:22 Gutierrez pits, but Vergne stays on track to start his own first timed run.

10:23 Hamilton returns to the pits after that three-lap run.

10:25 Vergne doesn't come round again, instead pitting after his second lap. He's onto three for the day.

10:28 Gutierrez is the only other man to have completed a lap so far this morning.

Raikkonen and Perez have gone out, but both stopped on the back half of the track and had to be recovered.

10:28 Which means we're yet to see Red Bull, McLaren, Williams, Caterham or Marussia. Lotus of course is missing the entire test.

10:29 Take two for Raikkonen and Ferrari - the Finn is back out in the F14 T, almost two hours after his first, failed attempt.

10:32 As a comparison to Hamilton's time, the fastest lap on day one of this test last year was a 1m18.861s. The first flyer of the first day, meanwhile, was a 1m35.607s, set by Felipe Massa for Ferrari.

10:32 Here's our technical expert CRAIG SCARBOROUGH's full analysis of the new Ferrari. His judgement on the unveiling spec... conservative:

Ferrari F14 T technical analysis

10:37 After our first two and a half hours of running, the order is:

1 Hamilton, Mercedes: 1m33.305s, 7 laps
2 Vergne, Toro Rosso: no time, 3 laps
3 Raikkonen, Ferrari: no time, 2 laps
4 Perez, Force India: no time, 1 lap
5 Gutierrez, Sauber: no time, 1 lap

10:39 Vergne is back out for Toro Rosso.

10:41 The Frenchman comes round for a second lap, and it looks like we'll have our second time of the day.

10:42 Indeed we do - Vergne clocks a 1m43.299s for his first flyer of 2014.

10:44 Vergne pits to bring his own three-lap stint to a close. Six laps total for the Frenchman now, just one behind Hamilton and Mercedes.

10:52 The day's two busiest man are at it again - Hamilton heads out in the Mercedes, followed very shortly be Vergne.

10:54 A new best - Hamilton comes round in a 1m29.662s.

Vergne, in contrast, is on half chat down the straight.

10:55 After that burst, Hamilton pits once more.

Vergne is still out though, and second time around dips down to a 1m41.398s.

10:58 First period of sustained running from Vergne. His third flyer yields a 1m39.161s, and also takes him to nine laps for the day, just one shy of Hamilton.

Raikkonen is the next best in terms of lap count, with two (only one completed under his own steam).

10:59 Another huge chunk for Vergne, who shaves three seconds off his previous benchmark to get down to a 1m36.530s.

That is still nearly seven seconds off Hamilton, but it is also the fifth lap of this stint - comfortably the longest run of this opening morning.

11:01 Vergne pits after that five-lap run, and we're back to quiet on the track.

11:02 Which is as good a time as any for a brief recap of the order:

1 Hamilton, Mercedes: 1m29.662s, 10 laps
2 Vergne, Toro Rosso: 1m36.530s, 11 laps
3 Raikkonen, Ferrari: no time, 2 laps
4 Perez, Force India: no time, 1 lap
5 Gutierrez, Sauber: no time, 1 lap

11:10 Suddenly the Jerez skyline is looking slightly ominous, with a few threatening clouds rolling in. Temperatures are still low - a modest 12 degrees C, with the track four degrees higher at 16.

11:11 Hamilton heads back out for Mercedes.

11:13 Hamilton hits 270km/h again down the main straight, and he's beginning to more visibly lean on the W05.

He's purple in S1, but his lap tails off in the middle split and he doesn't improve.

11:17 Another three-lap stint complete, Hamilton returns to the pits.

11:22 He's not worried about the current lack of running (see 0917), but AUTOSPORT technical guru GARY ANDERSON has been taken aback by the sheer number of problems teams have encountered on this first day:

"I was expecting people to have problems but I am a bit surprised there are quite so many!

"We still haven't seen Red Bull, McLaren, Williams, Caterham or Marussia - which we already knew was delayed - and Ferrari has only done one lap.

"It's the complications under the engine cover that is the issue and every time they open the garage doors they find a problem. But at approaching lunchtime on the first day you would expect at least to be doing installation laps. The pressure is building."

11:30 There is no official lunch break here at Jerez, but judging by an emptying pitlane - in terms of media and pit crews - we may be entering a slight lull (that's our bid to tempt more teams out).

11:30 After three and a half hours, we're still yet to see Red Bull, McLaren, Williams, Caterham or Marussia (the latter of course only shipped its car today, so isn't expected to run before Thursday).

11:34 Aha. Maybe we spoke too soon - Mercedes is readying for another run. Apparently Hamilton removing his cap is the giveaway (maybe we should start a cap watch):

@MercedesAMGF1: "Lewis' off-track head gear takes a break from duties; he's saddled up for another run... #KeepFightingMichael #Jerez"

11:36 Hamilton hasn't moved, but we do have track action as Gutierrez heads out, and then returns immediately.

11:38 The cap doesn't lie - Hamilton heads out and comes round for the start of another flyer.

11:42 Hamilton comes round in a 1m27.820s, around two seconds faster than his previous best...

11:42 ...but no sooner does he cross the finish line than he pulls to a halt in the first sector. Our third red of the day.

11:44 His Mercedes crew don't have far to travel at least. They're into the course car and on their way to the W05, which appears to have stopped between Curva Expo and Curva Michelin.

11:46 Scratch that - it seems Hamilton is in the Turn 1 barriers. Marshals are picking up bodywork on the main straight.

11:49 Looks like a fair bit of damage on the W05. The course car and marshals are cleaning the circuit well before Turn 1 too.

11:51 AUTOSPORT technical expert Craig Scarborough offers his view of that crash, and suggests it may have been caused by a failure:

@ScarbsF1: "Hamilton has just gone off track at T1, there was a lot of debris left on track as black rubber marks started, suggesting something's failed."

11:52 The car is back on the low loader and being ferried rapidly back to the Mercedes garage.

11:55 The debris has been cleared, and we're back to green.

We'll bring you the latest on that crash as it emerges.

11:56 Confirmation that a failure caused Hamilton's crash:

@MercedesAMGF1: "A car failure for Lewis put him off at Turn One. Cause to be investigated when car returns to the garage."

11:59 AUTOSPORT's spotters on the ground confirm that it was a front wing failure Mercedes are referring to.

It shattered well before Turn 1 and left Hamilton a helpless passenger, in much the same way as Fernando Alonso's wing broke in Malaysia last year.

Hamilton was able to climb out the car and appeared unhurt.

12:05 So, after four hours of the first test of 2014, the only cars to have set flying lap times are: Hamilton's Mercedes on 1m27.820 and Vergne's Toro Rosso on 1m36.530s.

We've also seen Ferrari (Raikkonen), Sauber (Gutierrez) and Force India (Perez) on track for installation laps.

Mercedes had looked the most impressive so far, until that front wing failure put Hamilton in the wall.

12:09 Lotus, which is absent from the Jerez test, is sure its design is legal:

@Lotus_F1Team: "We are confident our design complies with the FIA legal requirements - Nick Chester sets the record straight here"

12:12 Kimi is back on track in the Ferrari.

12:13 Could he be the third driver to set a time?

12:16 No, he comes in and Ferrari hides the car away again.

12:26 A lull on track now in the aftermath of Hamilton's accident.

12:27 We spoke too soon - Raikkonen is back out for Ferrari.

12:30 We might just have our third timed lap on the board - Raikkonen has headed into his first flyer of the day.

12:30 And he slots straight into second with a 1m33.131s.

12:32 Raikkonen heads back in after completing that three-lap stint.

12:39 Gutierrez, still with just two installation laps under his belt, heads out in the Sauber.

12:42 Caterham gets the annual lunch game going early (and also inform us they are close to launching):

@CaterhamF1: "Lunch is done (burgers, couple of salads, pasta or rather nice Asian salmon for you foodies out there) & we're nearing "fire up & go" time.."

12:44 Another short run for Gutierrez, who heads straight into the pits. The good news is we won't be quiet for long - Raikkonen is about to head out, if the rumble beneath us in the media centre is anything to go by.

12:46 Raikkonen isn't exactly pushing, but he does at least come round for the start of - potentially - his second flyer.

12:48 He's marginally quicker than his previous best - a 1m32.917s that time round, but still more than five seconds off Hamilton.

12:50 Raikkonen stays out and finds a good chunk of time next lap. He's down to a 1m30.674s, so he found two seconds alone on that last lap.

12:51 And into the 1m20s for Raikkonen, as his third lap of this run yields a 1m29.474s.

Gutierrez has just headed out to join him - only the second time today we've had more than one car on track.

12:53 That situation comes to an end almost as soon as we typed however, as both men dive into the pits.

12:58 Max Chilton, who was due to be driving today before Marussia's struggles, is on his way:

@maxchilton: "The yearly circus has begun! On my way to Stansted to catch a flight to Jerez! #TurboTime"

13:06 Still little happening on track. Ferrari has coined a phrase for 2014 testing - will it catch on?

@InsideFerrari: "Formula 1 at a snail's pace #WelcomebackKimi, #F14T, #ForzaFerrari"

13:07 Gutierrez, with four laps (none of them timed) under his belt, heads back out for Sauber.

13:09 Five hours in, and still only five teams have ventured out. The order so far is:

1 Hamilton, Mercedes: 1m27.820s, 18 laps
2 Raikkonen, Ferrari: 1m29.474s, 11 laps
3 Vergne, Toro Rosso: 1m36.530s, 11 laps
4 Gutierrez, Sauber: no time, 5 laps
5 Perez, Force India: no time, 1 lap

13:10 Gutierrez stays out this time, and duly sets his first flyer of the day, a modest 1m42.257s.

13:12 Caterham's announcement is music to our ears:

@CaterhamF1: "Has to be positive news that @Ericsson_Marcus is in overalls and now in a briefing with the engineers..... soon come #TeamGreen 2014...."

13:16 In the (hopefully temporary) lull, here is Claire Williams, deputy team principal at the Grove-based squad, on why this year's Jerez test is so crucial for every team:

"Because of the regulation overhaul, the first test in Jerez is one of the most important pre-season tests that the sport has had in a number of years.

"This car is a complete revolution; it’s not an evolution from a previous year so the engineers and drivers are going to be under a considerable amount of pressure.

"We will be concentrating on systems checks to make sure everything is functioning as it should and then working towards reliability, which is going to be a potential game changer, certainly in the early races of the season.

"It’s going to be fascinating to see where everybody is over the coming weeks."

13:19 Williams of course is one of four teams yet to officially unveil their 2014 challenger, but they did release an early image of its Mercedes-powered FW36.

13:20 Caterham confirms to AUTOSPORT that it will be out 'within the next 10 minutes'.

Watch this space...

13:26 We have eyes in the pitlane waiting for the first glimpse of the Caterham, and we're also on our way to speak with Daniil Kvyat and teams up and down the pitlane. Busy busy (even if the track isn't).

13:27 That tactic seems to be working a treat today. As we write that it is quiet, Vergne heads out for Toro Rosso.

13:28 He was set to be joined by Gutierrez in the Sauber, but the Mexican comes to a stop in the pitlane and has to be wheeled back into his bay.

13:31 With Raikkonen tasked with Ferrari driving duties for the first two days at Jerez, Alonso is playing the AUTOSPORT Live lunch game. We reckon he wins (we had a baguette):

@alo_oficial: "Restaurante montana."

13:33 Vergne dives straight back into the pits, which allows the pitlane photographers time to scarper down to Caterham, where the first sighting of the Renault-powered F1 challenger is eagerly awaited.

13:38 Seems like Caterham is being given the respect of the pitlane - the track is empty, and the team's 2014 car is overdue.

13:40 Aha. We have a guttural roar, and the new Caterham is sparked into life (we can't see it yet, but the photographers can).

13:43 Confirmation that Mercedes won't be heading back out: the end-of-day press briefing will take place in 10 minutes "owing to the early conclusion to the team's running today," a team release confirms.

13:46 It must be something in the food. Shortly after lunch, and moments after Caterham fire up, Williams is almost ready too:

@WilliamsF1Team: "Car has fired up and is now being set up ready to run....we are hoping to show you the #FW36 soon!"

13:56 The apparent impasse is broken as Vergne heads out in the Toro Rosso.

13:57 McLaren meanwhile confirms to AUTOSPORT that it will keep pushing to run today, even if it means getting one installation lap minutes from the day's end.

Even so, it is apparently unlikely to appear today. The problem is electronic/hydraulic.

13:59 Despite his earlier crash, Hamilton is upbeat about his first day in the W05:

"For me it's an incredibly positive start to be the first car out on track and completing a good number of laps.

"Of course, it's unfortunate to end the day early when everyone has worked so hard and we had looked like easily completing the most mileage of anyone here today."

JONATHAN NOBLE is speaking with the Briton, who still heads the day one timesheets, as we type. Look out for more reaction later.

14:04 With two hours to go, the leaderboard has changed little since our last update:

1 Hamilton, Mercedes: 1m27.820s, 18 laps
2 Raikkonen, Ferrari: 1m29.474s, 11 laps
3 Vergne, Toro Rosso: 1m36.530s, 14 laps
4 Gutierrez, Sauber: 1m42.257s, 7 laps
5 Perez, Force India: no time, 1 lap

14:08 One man's disadvantage is another man's opportunity, or so the saying goes.

The smaller teams on the F1 grid are certainly hoping the sweeping rule changes present the chance for a shock or two, as Force India COO Otmar Szafnauer explains:

"Like most things in life, having more resources usually wins!

"We are competing against manufacturer teams with big budgets so you would expect their well-funded research will help them find the optimal solutions.

"But you never know: we've been focused on 2014 for a long time and we're pleased with the car we've produced so there's always an opportunity."

14:09 It sounds throaty, it is sporting a very obvious protruding nose, and it is also alive.

Caterham's 2014 machine heads out in the hands of new recruit Marcus Ericsson.

14:12 Ericsson heads in, Raikkonen heads out.

14:13 Caterham's design is bound to provoke debate, but looking from above as it cruises down the pitlane it actually looks quite good (we might be relatively alone in that sentiment).

14:15 Raikkonen banging in the laps now (well, relatively speaking).

He comes round for his third timed lap. He set a 1m29.655s last time around, less than two tenths shy of his current best.

14:16 Like we said, Caterham's 2014 car is bound to provoke debate:

@CaterhamF1: "Never seen Tweetdeck columns scroll so quickly. 2014 F1 cars might not be pretty, but they're certainly giving you something to talk about!"

14:19 Raikkonen brings his four-lap run to an end. He's up to 14 for the day now - Hamilton, on 18, still leads the way.

14:20 With Ericsson joining Perez in venturing out (but not setting a time), we're now waiting to see if the final three drivers will make it out today.

The trio in question? Sebastian Vettel at Red Bull, Jenson Button at McLaren, and Valtteri Bottas at Williams.

14:27 Vergne heads out for Toro Rosso. He only needs to do five more laps and he'll have covered more miles than anyone else today.

14:28 Team boss Franz Tost earlier confirmed that Toro Rosso had built more of the STR9 than it had any other chassis.

14:29 And the red flag is out again. Vergne has stopped between turns 4 and 5.

14:31 A recovery truck has already made it to Vergne. It's a shame as Toro Rosso has provided us with more laps to see than most today.

14:35 Caterham has just conceded its new car is the CT05, and not the CT04 as originally billed!

14:40 The Toro Rosso has been removed so we're waiting to go green again for the last hour and 20 minutes of day one.

14:41 And there it is. We're green again.

14:42 The Toro Rosso failure means Vergne has been credited with 15 laps, the same as Kimi Raikkonen's Ferrari, which stopped on its first lap out the pits this morning but has since gone second quickest.

14:45 Force India decides to go out.

14:46 Perez has yet to record a flying lap, so maybe this time?

14:48 Sadly - for us - once again the answer is no.

14:49 Now Kimi heads out for Ferrari.

14:53 And Kimi goes quicker, 1m28.686s. That's only 0.9s down on Hamilton's best from earlier in the Mercedes.

14:54 And now he goes fastest of all, 1m27.427s.

14:56 Our F1 editor EDD STRAW is down in the pitlane and waiting for the first glimpse of the Williams, which is due imminently.

He's just caught up with the team's new recruit Felipe Massa too, with the Brazilian reportedly 'eagerly anticipating the first run of the car'.

14:56 And again, 1m27.104s. A decent run this time from Kimi.

14:58 Raikkonen pits, but it's a quick stop and he goes straight back out. He has now done 20 laps, more than any other driver.

14:59 AUTOSPORT's EDD STRAW reports Kimi was pressing on a bit with that last run, saying there was a bit of wheelspin and a rear-end wobble out of the last corner.

15:00 And Valtteri Bottas has taken the new Williams out onto the track at last.

15:02 Bottas and Raikkonen have now pitted. But once again it's a quick stop for the Ferrari, which heads straight back out.

15:03 Our first glimpse of the new Williams in the flesh (so to speak):

@WilliamsF1Team: "And here she is!! Hope you like her! #BO77AS makes his way in track!"

15:04 Raikkonen is continuing his in-quick stop-out run.

15:05 As Williams celebrates one milestone, Caterham's Marcus Ericsson enjoys his own:

@Ericsson_Marcus: "Just done my first lap as a @CaterhamF1 driver. Very proud moment! Initial feeling good, but now the hard work starts. #F1 #Jerez"

15:08 With Raikkonen back in the pits, it is now Perez's turn to head out in the Force India.

15:09 And he's gone past the pits onto another lap, so perhaps we will get a lap time for the Force India.

15:13 Toro Rosso are reporting they hope to be back out soon.

@ToroRossoSpy: "Fuel, tyres... soon we'll be ready for the track again!"

15:14 Perez has pitted without setting a time, so we're still waiting for that list to grow above four.

15:16 Just 45 minutes to go and here is a reminder of who has completed the most laps:

1 Ferrari, 24
2 Mercedes, 18
3 Toro Rosso, 15
4 Sauber, 7
5 Force India, 4
6 Caterham/Williams, 1

15:21 Raikkonen heads out again. There is a good chance he'll end up on top of both the timesheet and most laps completed list.

15:24 It's a 1m33s lap for the Ferrari, some way off his best. Having said that, it's still quicker than anyone else has managed except Hamilton!

15:28 Bottas takes the FW36 out for its second run.

15:29 Kimi does a 1m28, the third fastest time of the day.

15:30 Bottas comes in and the Williams team roll the car back into the garage.

15:31 A 1m27.9 for Kimi this time around, which is also his 30th lap today.

15:32 And now Raikkonen comes in, leaving the track empty.

15:38 Rain has now hit Jerez, so that'll probably be it for today.

15:40 Official wet tyre running is set for Friday. They can move it sooner if conditions dictate, but with just 20 minutes left to go today it seems unlikely anybody will go out.

15:44 So, a run down of the times and laps completed.

1 Raikkonen, 1m27.104s (31 laps)
2 Hamilton, 1m27.820s (18 laps)
3 Vergne, 1m36.530s (15 laps)
4 Gutierrez, 1m42.257s (7 laps)
5 Perez, no time (4 laps)
6 Bottas, no time (2 laps)
7 Ericsson, no time (1 lap)

15:45 Well, we were wrong! Perez has decided to head out. The rain looks like it will be brief. We've got dark clouds and some blue sky.

15:45 Sebastian Vettel takes the Red Bull out for its first run.

15:49 Vettel has completed the installation lap for the RB10, while Perez has now set a flying lap time.

15:51 Bottas takes the Williams back out, Perez pits.

15:54 Bottas goes third quickest with 1m30.082s.

15:55 Now that the Red Bull has finally appeared, here's a reminder of the analysis of the RB10 by our technical expert @ScarbsF1

Tech analysis: Red Bull's hidden complexity

15:56 So, with just five minutes to go, we've got Perez and Vettel on track again as Bottas comes in.

15:59 Bottas takes the FW36 out, just as Perez records 1m38.434s.

16:00 As the first day draws to a close, McLaren reveals a little more about what has prevented it taking to the track today:

"Despite firing up successfully at the MTC last week, the car was predominantly affected by electrical issues during the day.

"The subsequent dismantling, inspection and re-installation of several major components ultimately meant we were unable to conduct any running today.

"We’re re-installing key systems on the car overnight, with the expectation that Jenson [Button] will begin the car’s installation programme tomorrow."

16:01 Perez goes quicker and is now fourth for Force India on 1m33.161s.

16:02 And the flag is out to end day one of the Jerez test, with Bottas and Perez still on track.

16:06 With running now finished, here are the best times and laps completed:

1 Raikkonen (Ferrari), 1m27.104s (31 laps)
2 Hamilton (Mercedes), 1m27.820s (18 laps)
3 Bottas (Williams), 1m30.082s (7 laps)
4 Perez (Force India), 1m33.161s (11 laps)
5 Vergne (Toro Rosso), 1m36.530s (15 laps)
6 Gutierrez (Sauber), 1m42.257s (7 laps)
7 Vettel (Red Bull), no time (3 laps)
8 Ericsson (Caterham), no time (1 lap)

16:10 And that's it for the first day of running for the 2014 breed of F1 cars. Thanks for joining us and please do so again tomorrow, when we hope more of the cars will make it out on track.