Rosberg laments Williams's poor pace

Although Rosberg was always set for a poor grid position because of the ten-place grid penalty he was given for crashing in the pitlane in Canada, even he was surprised to be only 15th quickest overall - with teammate Kazuki Nakajima one place further back.

"I knew it was going to be slightly hard for us here, but to be so far off the pace is quite surprising," said Rosberg, who will start from the last place on the grid because of his penalty.

"If everything had gone perfectly, I may have been in P14, but that's not good enough. We had to compromise our pace this afternoon because of the grid penalty, but that should only have cost us a tenth: not this much.

"We've had a good car in the last two races, and have been running in the top six, but there are some tracks, such as Magny-Cours, that don't seem to suit our car very well."

Williams's form this season has been up-and-down, and although the team have started working on their weaknesses, Rosberg thinks there is no quick fix.

"We started to address this problem at the last test, but it's going to take some time to resolve it. Getting a decent result from P15 would be difficult enough but, with the ten-place penalty, it's going to be even harder.

"That's just how it is, though, and we need to work out how we're going to play it."

Williams director of engineering Patrick Head added: "A very disappointing qualifying for us today. It's obvious that the car isn't strong here, but equally we didn't get the best out of it this afternoon as we were setting better times in practice with more fuel on board.

"Hopefully we can pull something out of this tomorrow, but, ultimately, we need to raise the car's performance."