Lewis Hamilton and Mercedes have called it a day with just over an hour remaining. The Briton, who had clocked up 91 laps, stopped at the entry to the pit-lane earlier in the session with a water system issue.

And the team say investigations have revealed a water leak from a failed part. "The crew are now working hard to get the car ready for a return to action tomorrow," adds the team.

F1 journalist Dan Knutson in Jerez: "A contingent of Lewis Hamilton's fans are in the grandstand directly across from the Mercedes pit.

"They have been cheering and waving every time he comes into the pits and he has been waving back at them from the cockpit of the car."

Quick work from the marshals means we're back up and running already.

We've got our first red flag of the day - and guess who is responsible. Yep, it's the Lotus of Pastor Maldonado. The Venezuelan has stopped on track.

With a little over an hour remaining, here are the headlines:

• Sebastian Vettel sets the pace in the Ferrari

• Lewis Hamilton continues Mercedes' strong form, clocking up nearly 100 laps, but has brief stop with water system issue

• Red Bull's running limited after Daniil Kvyat breaks front wing

• The new Lotus takes to the track for the first time

• McLaren's struggles continue as Jenson Button manages just five laps, one fewer than team-mate Fernando Alonso managed yesterday

Richard Alpin:, external McLaren have done the best business by keeping JB. McLaren and Ferrari joint worst in [terms of them] signing Alonso and Vettel.

Image source, Getty Images

After spending yesterday and today on the sidelines, Felipe Massa will finally get his chance behind the wheel of the Williams tomorrow and Wednesday.

Image source, Getty Images

With the conditions as they are, it looks like Sebastian Vettel will top the times for the second successive day - not a bad way to start his Ferrari career, eh?

Lotus:, external It's time for another outing. Let's see what the #E23 can do in the afternoon drizzle.

Still no sign of the McLaren with less than two hours to go.

We have action again as Sebastian Vettel heads out in the Ferrari. Williams' Valtteri Bottas gets involved, too, in the Williams, with Daniil Kvyat doing a practice start before hitting the track.

Andrew Benson
Chief F1 writer

"The long delays at McLaren are rooted in the car's packaging - on a design described as 'quite extreme, quite aggressive, quite innovative' by Fernando Alonso on Sunday. The team thought they had fixed overnight the problems that hit Alonso on Sunday but the same problem recurred for Jenson Button on Monday morning. The part in question - the identity of which McLaren will not reveal - is buried so deep in the car that it is taking a lot of time to get at it and fix it. But a spokesman said the team were 'quite positive we've sorted the problem'.

"Meanwhile, 'aggressive' would also be an apt word for Honda's approach as it prepares for its return to F1. The Japanese company will have different engines at the next test than the one that is in the car now, and then different engines again at the last test - the race engines. These last ones will incorporate every single modification made on the previous two versions. Honda needs to homologate its initial design with the FIA by 28 February, but will have some development still available during the season."

The light drizzle is not ideal for the teams. I suspect Mercedes won't be too bothered, as they've gathered the most data of anybody. For McLaren, they're still busy working on fixing a problem, so won't be out for a bit yet anyway. Red Bull are limited to what they can do without a front wing. For the others, it will be valuable time lost.

Mercedes:, external A bit drizzly and grey here @circuitodejerez as we finish up lunch - what do they say about the rain in Spain?

It's all quiet out on track with a little over two hours to go!

F1 journalist Dan Knutson in Jerez: The new McLaren was designed as what Ron Dennis describes as a "densely packaged concept."

"He said that every single thing is so embedded in the car that to get to anything requires removing layers of heat shields or other components.

"So that certainly is a contributing factor to why the car is spending so much time in the garage."

Image source, Fernando Alonso

While Jenson Button is in the McLaren, his team-mate Fernando Alonso is chilling with fellow Spaniards Carlos Sainz, a two-time rally champion, and his son Carlos Sainz Jr, who will make his F1 debut in a Toro Rosso this year.

Andrew Benson
Chief F1 writer

"A chink of light for McLaren, perhaps? Jenson Button has done five laps so far today after Fernando Alonso's six on Sunday, all of them stuttery. This follows five laps over two days with the 2014 hack Honda test car in Abu Dhabi last November.

"McLaren have been very coy about what is wrong in Jerez, with racing director Eric Boullier saying on Sunday it was "a few electrical issues" and a spokesman saying on Monday that there were "ancillary issues".

"But now the team say they think they have found the problem and hope to have the car out again before the end of the day. Everyone is keen to find out whether the very interesting-looking MP4-30 has solved the issues with lack of front downforce that plagued McLaren last year - and, of course, how good the Honda engine is."

Sebastian Vettel has the track to himself in the Ferrari. The German driver still leads the way ahead of Lewis Hamilton, Valtteri Bottas, Max Verstappen, Felipe Nasr, Pastor Maldonado and Jenson Button.

Image source, Getty Images

Frenchman Romain Grosjean is in the paddock today - he's expected to get his first chance to drive the Lotus tomorrow. Pastor Maldonado is behind the wheel today.