Mercedes pair Lewis Hamilton and Nico Rosberg on Friday wrote off their chances of beating ‘ballistic’ Red Bull in Sunday’s Hungarian Grand Prix after a day of struggle with Pirelli’s new tyres.

The Briton and the German, one of whom has been fastest or second-quickest in qualifying at the last seven Grands Prix, said they did not have a hope of victory.

Hamilton, the 2008 champion, wound up sixth fastest in the afternoon’s free practice session, one place ahead of Rosberg on a sweltering day dominated by the Red Bull pair of Sebastian Vettel and Mark Webber.

Rosberg said the hot conditions were the worst possible for Mercedes as tyre-wear remains the team’s most serious weak point.

Rosberg said: “Red Bull looked very, very good today — I don’t think we have the speed. Red Bull seems very quick and some other teams are also going to be quicker than us in the hot conditions of the race.

“We just need to make the most of it and get a lot of points. The hotter it is, the worse it is for us and the more we’re going to struggle. And this is likely to be the hottest race of the year. It’s going to be tough.”

Hamilton said: “We don’t seem to have the pace that we had at the last race but we’ll make some changes tonight and try to understand it.

“We came into the weekend on the back foot trying to understand the tyres and we did a lot of laps today. We’ve learned quite a lot, we’ve made some changes and we can make some better changes for tomorrow.”

He agreed with Rosberg that Red Bull was out of reach.

“I was told that on the same laps on long runs, Mark Webber was about eight tenths ahead at some stages, so that’s interesting…” said Hamilton.