McLaren team principal Martin Whitmarsh said he was hopeful of progress from the team in this weekend's British Grand Prix despite a difficult start to the weekend at Silverstone.

After losing FP1 to the weather conditions, Jenson Button and Sergio Perez ended the second 90-minute session in eleventh and 14th on the timing sheets.

With McLaren having planned a series of upgrades for this weekend, Whitmarsh admitted that the poor conditions had been frustrating for the team but said he remained hopeful of forward progress as the Woking-based outfit seeks to rebound from a tough start to the year.

"We do seem to have been affected by an unusually high number of rained-out Friday practice sessions this year. While it's the same for everyone, it can be frustrating when you're trying to run through a large and intensive programme of testing.

"While we were able to get quite a lot of mileage under our belts, there's still plenty of work left to do. It's been a difficult day, but with drier weather forecast for the next two days, we're hopeful of making progress."

Button added the team would now need to sit down and examine the data to discover if the changes made to the car had had the desired effect.

Although he admitted that the balance was better than last time out in Montreal, the Briton insisted that there was still a lot to do if McLaren wants to challenge at the front.

"Despite this morning's washed-out session, I think we got in all the running that we needed this afternoon, and we managed to get through most of our programme - including some running on Pirelli's test tyre," he said. "The car doesn't feel too bad out there, and the balance is reasonable - it's better than it was in Canada - but we're still some way off the pace.

"Still, the engineers have lots of data to analyse, so they'll be able to find out whether the new parts have made the improvements that they'd predicted."