Nico Rosberg has bitterly lamented Mercedes Grand Prix's worsening form in F1 2010, admitting that he moved to the reigning double F1 World Championship-winning outfit from Williams 'because I thought I'd have a car capable of winning' - but confessing that instead, the season is rapidly degenerating into a 'disaster'.

Having sat second in the world championship standings earlier on in the campaign off the back of a front row start in Malaysia and impressively composed back-to-back podium finishes in Sepang and Shanghai, Rosberg has since slipped to seventh spot in the title chase with just 25 points from the last five grands prix, as the Mercedes MGP W01 has fallen increasingly away from the front-running pace.

Despite having insisted during the week that he has far from given up on his chances of clinching the coveted crown [see separate story - click here], it seems the frustration and disappointment is beginning to tell for Rosberg, with the European Grand Prix in Valencia last weekend marking inarguably the nadir of the season so far, as neither he nor record-breaking team-mate Michael Schumacher made the top ten in qualifying for the first time all year, and to add insult to injury both subsequently found himself outpaced by the two Williams cars on race day.

"This is a disaster," the 25-year-old blasted in an interview with the Cologne Express. "The problem with the tyres is well-known within the team. For weeks, we have said we would move forward but nothing [has] happened - in fact, we're going backwards. If you start in twelfth behind both Williams' [in Valencia], who were nowhere weeks ago, what can you expect from there? I went from Williams to Mercedes because I thought I'd have a car capable of winning."

Rosberg was more optimistic, however, looking ahead to the British Grand Prix around the revised Silverstone next weekend. The son of 1982 F1 World Champion Keke Rosberg - the man whose pole position time for the 1985 British Grand Prix around the same circuit stood for 16 years as the fastest single lap in the sport's history at an average speed of an incredible 160.9mph - finished fifth at the celebrated 'Home of British Motor Racing' last year, and a similar result twelve months on would evidently be more-than welcome.

"Silverstone is a great circuit, and one of those tracks which provides a real challenge for you as a driver," he enthused. "I think every driver loves to race there. The layout is demanding with the very quick corners, and it will be interesting to see the new changes in the Arena complex for this year.

"The atmosphere and the fans are always fantastic at Silverstone, and it will be even better this year with our factories just down the road and the support of everyone at the team. We will be going back to Brackley after the race to see everyone, and it would be nice to get a good result to reward their hard work. It's been tough for us over the last few races, but we are working hard to improve and I am confident we will get there."