London: Less than a week after writing off his hopes of winning this year's drivers' title Lewis Hamilton did an about turn and pledged to produce a typically thrilling bid for victory in next week's British Grand Prix - and reboot his challenge.

The 26-year-old Englishman sounded much more upbeat than he had done when defending champion Sebastian Vettel had turned last Sunday's European Grand Prix into a procession and opened up a seemingly unassailable lead in this year's drivers championship.

"I know what we are up against, but nothing is impossible," he said, during one of his events. "And what we all really want is a one-two - think what that would do for British sport and the fans.

"It would feel massively special to us. Hopefully one day there will be a younger version of me at Silverstone looking up at a photo of myself and Jenson on the podium."

Hamilton, who is currently fourth and 89 points behind Vettel, made a point of being upbeat and positive when he met around 180 fans at the McLaren factory on Friday.

The event was a 'fans forum' organised by the Formula One Teams' Association (FOTA) to discuss sporting and technical issues, but it was clear that the highlight of the day for the supporters was to see, and ask questions of, Hamilton and Japanese driver Kamui Kobayashi.

Hamilton, back in Britain for the build-up period to the British race, had earlier used his Twitter account to tell fans to ignore his comments as reported in the newspapers following Sunday's race in Valencia.

He had said then that Vettel had an unassailable lead and there was no hope of him winning the championship.

He added: "It's never over until it's over. We're only coming up to halfway and if we were to win all the other Grands Prix then we can still win the championship. There's still a big gap, but nothing is impossible."

On Twitter, Hamilton had said: "To all our supporters, ignore what u read in the papers On Friday. My team will never give up & I WILL NEVER GIVE UP!!!! Bring on Silverstone, ur support will make a world of difference to us. I'm going to the factory now to do all I can with our team. Lewis."