SILVERSTONE, England - A sense of urgency seems to be creeping into the Ferrari, Lotus and Mercedes paddocks ahead of the 2013 British Formula 1 GP.F1 news was dominated by the abrupt announcement that Red Bull's Mark Webber will leave F1 in 2014. For the teams competing for the Drivers' championship the focus remains on Webber's team mate, Sebastian Vettel.Ferrari's Fernando Alonso, second in the 2013 title race, said: "I think he's doing a fantastic job. I think he's been nearly perfect in all the races with no negative races, always performing well in qualifying and doing very good races."'NEED TO KEEP FIGHTING'Vettel has shaken off some early-season tyre troubles and a controversy with Webber at the 2013 Malaysian GP. He's back to his dominanating form, with the surest sign being his performance at the 2013 Canadian GP in which he beat Alonso by 14 seconds.Vettel has a 36-point lead over Alonso with 12 races left. Lotus driver Raikkonen is another eight points back in third and Mercedes' Lewis Hamilton is 11 points behind in fourth.Despite extending his lead, Vettel has tried to dampen expectations that the championship is already his, insisting he was trailing at this time in 2012 and needed a string of late-season victories to overtake Alonso. Should he win his fourth consecutive Drivers' championship, Vettel would match the exploits of F1 legends Juan Manuel Fangio and Michael Schumacher.Vettel's challengers understand they need to start beating him. Alonso said: "We need to keep fighting, we need to keep pushing and we need to recover from the bad races. I think Red Bull is performing really well, improving compared to the first part of the championship, so we really need to raise our game if we want to catch Sebastian - he's doing a fantastic job."Hamilton agreed: "He's performing as the World champion that he is and will be difficult to catch but I don't think it's impossible. From our side, we've already closed quite a huge deficit already but of course we want to do better. Fernando's a lot closer. I think once they sort out their qualifying they'll be able to match the Red Bulls, if not beat them. We need to do a lot more work."Hamilton said Mercedes was still having tyre trouble and struggling to translate qualifying pace into races.'TRY TO IMPROVE THE SITUATION'Raikkonen spent much of the day fielding questions about a possible move to Red Bull. He was more worried about getting his season back on track after poor finishes in the past two races in Monaco and Canada. "It's not ideal . We can only try to improve the situation. If we can improve a lot and there are problems for the others positions can change quickly. There's still a lot of racing to go..."Vettel's Red Bull team mate Webber announced that he's signed a multi-year contract and will compete in Porsche's new LMP1 sports prototype at the Le Mans 24 Hours race and in the World Endurance championship in 2014.The team only learned of Webber's decision on June 27 and said it would take its time to find a replacement - with Red Bull principal Christian Horner simply saying he "wanted a fast driver". "We want to field the best two cars we can in 2014. We are in a fortunate position where there are quite a few drivers who would like to drive a Red Bull and we have two talented young drivers (Jean-Eric Vergne and Daniel Ricciardo) that we have been developing in Toro Rosso. We don't need to rush into a decision."