Championship leader Nico Rosberg grabbed pole position for the British Grand Prix from a crazy qualifying session at Silverstone to again put Lewis Hamilton in the shade.

Hamilton was on course for top spot on the grid approaching the dying stages of a wet-dry session until pipped at the post by Mercedes team-mate Rosberg, with Hamilton backing off on his final run to leave him down in sixth.

After mistakes in qualifying at the last two grands prix in Canada and Austria, on this occasion it appeared to be misjudgement that cost the Briton dear, and again leaves him playing catch-up in the race to Rosberg.

Rosberg will be joined on the front row by Red Bull's four-times world champion Sebastian Vettel, with McLaren's Jenson Button third - his highest grid position since the final race of 2012 in Brazil - for his home race.

Hamilton could offer no explanation as to why he aborted his lap as he said: "I don't know, I don't have much of an answer. I just decided not to do the lap."

Asked by the BBC as to whether he backed out as he perhaps felt he would not improve, Hamilton replied: "Obviously not. I don't have anything to say to you at the moment."

BBC pundit and former team principal Eddie Jordan, though, pulled no punches with regard to Hamilton's latest mistake as he said: "It's a huge error and Lewis Hamilton, you're to blame."

Hamlton was in top spot after the first run in Q3, and come the start of the second run it appeared as if the track would be too damp in places for any driver to improve.

But that was far from the case as first Force India's Nico Hulkenberg went quickest and then Red Bull's Sebastian Vettel.

As for Hamilton, he backed off in the middle sector down the Hangar Straight, yet directly behind him Rosberg flashed by and went on to take his fourth pole of the year, and third in the last four races.

Behind the top three will be Hulkenberg ahead of the second McLaren of Kevin Magnussen, and then a lowly, downbeat Hamilton.

Force India's Sergio Perez starts seventh, with Daniel Ricciardo in his Red Bull eighth, with the Toro Rosso duo of Daniil Kvyat and Jean-Eric Vergne ninth and 10th.

Rosberg hailed the decisions taken by his team in the final session as the reason behind his latest pole.

Rosberg said: "It was definitely quite a crazy qualifying, it was changing all the time and that makes it very difficult.

"All in all it was a really good team effort, everyone working together, my engineers and me making the right calls."

In gaining another edge over Hamilton, Rosberg added: "Of course, in regards to the championship, it is good Lewis is down in sixth.

"It will take him some time to fight through, but I expect him to come through and we will be fighting each other."

The variable conditions caused havoc in the opening 20-minute period in particular, with Williams and Ferrari paying a heavy price.

All drivers made an initial run on the intermediate wet tyre, but as the track slowly dried in places, the call was made to switch to the medium-compound dry tyre.

It resulted in a mad scramble over the closing few minutes, and with some slipping and sliding as a few drops of rain scattered the track, yellow flags were also in evidence, forcing drivers to slow and ruin lap times.

Come the end of Q1, there was the unusual sight of Marussia duo Jules Bianchi and Max Chilton as high as fourth and sixth respectively.

Conversely, Ferrari pair Fernando Alonso - who spun on his final lap to destroy his chances of making Q2 - and team-mate Kimi Raikkonen were left languishing down in 19th and 20th.

Ahead of them, just a fortnight after locking out the front row in Austria, were Williams duo Valtteri Bottas and Felipe Massa.

Neither Marcus Ericsson, who went hurtling off track at one stage to spark the late flurry of frantic action, nor Caterham team-mate Kamui Kobayashi set a time within the 107 per cent rule of the quickest in Q1 in Rosberg.

Both drivers are now at the mercy of the stewards as to whether they will be allowed to race, although it is almost certain they will not be punished.

Come Q2, and with the track again damp at the start, intermediates were the first order of the day before another switch to slicks.

For a fleeting moment there was a possibility of a Marussia making it into the top-10 shootout, only for Bianchi to wind up 12th, missing out by just over half a second, but still clinching the team's highest grid slot in their four-and-a-half years in F1.

Lotus' Romain Grosjean finished 11th, whilst behind Bianchi was Chilton, although the Briton faces a five-place grid penalty for a gearbox change and will start 18th.

Esteban Gutierrez qualified 14th, but will drop to the back of the grid due to a 10-place penalty incurred in Austria for an unsafe release.

The Mexican ended Q2 by sliding off the track and into a barrier to mark a miserable qualifying for Sauber as Adrian Sutil beached his car in the gravel in Q1 and did not take part in the second session.

Lotus' Pastor Maldonado, who was ordered to stop his car in Q2 due to a fuel-pressure problem, qualified 15th, with Sutil 16th.