McLaren-Mercedes star Lewis Hamilton assures that he has 'turned all the negatives into positives' following his uncharacteristically downbeat pronouncement in the wake of last weekend's European Grand Prix - and heading towards the British Grand Prix on home turf at Silverstone, he insists 'it's never over until it's really, really over' in his quest for a second F1 World Championship crown.

In a not unfamiliar pattern for the British ace this year, Hamilton claimed in the immediate aftermath of his distant fourth-place finish around the streets of Valencia on Sunday that 'it is finished really, in the sense of the championship' since 'we cannot beat the Red Bull right now' [see separate story - click here] - and then almost immediately backtracked the following day by asserting via Twitter that 'my team will never give up & I WILL NEVER GIVE UP!!!!' [see separate story - click here].

Now, despite languishing a gaping 89 points adrift of runaway F1 2011 World Championship leader Sebastian Vettel in the title standings and nobody seeming to have a consistent answer to Red Bull Racing's searing pace, the 26-year-old reveals that he is fired-up to shine in front of his adoring partisan supporters at Silverstone - a circuit around which he had suggested McLaren would 'really, really struggle'. And beyond that, well, 'nothing is impossible', he asserts.

"I feel I've turned all the negatives I may have had into positives," Hamilton told BBC Sport. "I'm quite a realistic person so I know what we're up against, but nothing is impossible. The British Grand Prix, we're excited to go there and what we really want is a one-two [with McLaren team-mate Jenson Button] - what that would do for British sport and for our would feel massively special to us.

"We're only just coming up to halfway [through the season], so there's still a long way to go. If we were to win all the other grands prix we could still win the championship, so it's never over until it's really, really over. Of course he (Vettel) is pulling quite a big gap, but nothing is impossible."

Button was present alongside Hamilton at a private, star-studded preview of Getty Images' 'Driven to do Better' Santander British Grand Prix Photographic Exhibition in London last night (Tuesday), and whilst agreeing that Vettel will take some catching - the 2009 F1 World Champion is marginally closer at 'just' 77 points in arrears of the German - he also agrees that there will be no let-up in the slightest in McLaren's bid to overhaul its rival as he personally targets his first rostrum finish at Silverstone in eleven days' time.

"I think Lewis and myself were a bit negative after the race [in Valencia], but looking at it now, we have some good improvements for Silverstone," the 31-year-old told BBC Sport. "I don't know whether that's going to be enough to fight with the Red Bulls and get on the podium, but we've got improvements and we're positive we are going to get the best out of them.

"We want to put on a great show for the British fans and I think that's why we were a bit negative after the last race, because we get so excited about the British Grand Prix and you want to perform well. I wouldn't say there's more pressure, but you want to put on a good performance because you get so much support there.

"[Vettel] has got a big advantage after eight races, but who knows? We're not going to stop trying - we're going to be trying our best. We've got a fantastic team, and if we keep pushing hard we'll slowly pull them back - I hope so. It's tricky, because they (Red Bull) are doing a great job and the only people that have beaten them are us - Lewis and myself - so we are the challengers."