LONDON, England - Formula 1 champions Lewis Hamilton and Jenson Button have welcomed the idea of a London GP although others were sceptical about whether it would ever pick up speed and become reality.With the 2012 British GP at Silverstone booked for July 8, sponsor Santander revived a long-cherished idea of a race in the British capital with a computer-generated impression of how it might look.The concept, generally considered a bit of fun to create some headlines and buzz ahead of the country's annual race, was due to be presented later with F1 supremo Bernie Ecclestone, 81, among the guests. He has long backed a London race although the cost, logistics and environmental concerns have been obstacles.ARCH OBSTACLE"Think what it would do for tourism," he told The Times. "It would be fantastic, good for London, good for England - a lot better than the Olympics."Maybe we would front it and put the money up for it," added the billionaire, who usually drives a hard bargain on fees.Details that emerged on Thursday presented an obvious and very solid problem with the track threading through the monumental Admiralty Arch off Trafalgar Square. That would be very much an accident waiting to happen, given that ordinary traffic goes through its three narrow arches in single file and there is no way around it.McLaren's Button, 2009 champion, said he loved the idea - in principle anyway. "Do I like the idea of having a London GP? Yes, the more grands prix in the UK the better," he told Reuters, "but I'm not sure where it would be. There was talk of using the Olympic Stadium, which could be quite a lot of fun."I'm not sure you would be able to close down London for a GP, but it's a nice idea."'GREAT, IN THEORY'Bookmaker William Hill was sceptical. It offered odds of 33-1 that there would be NO race in London until at least 2016."The idea of a London GP is a great one, in theory, but in practice it will take a great deal of preparation. We cannot see it happening for some time."Ecclestone was involved in discussions with the city's former mayor Ken Livingstone at one point but it came to nothing. The current incumbent, Boris Johnson, a famously keen cycling fan who has also penned the occasional car review in his journalistic career, expressed qualified support."I'm always interested in projects that attract jobs and bring growth," he said, while expressing concern about air quality and noise.The possibility of using the area around the new Olympic stadium in the east part of London has been mooted, with one of the companies on a short list to take over the facility after the Games talking of putting on a GP there.'IT WOULD BE SENSATIONAL'Ecclestone denied involvement in that bid when asked by Reuters but has said he would be interested in any proposal once the relevant permits were obtained.Hamilton, McLaren's 2008 champion and a winner at Silverstone, was also keen on the general idea. "I was looking over the city and a GP here would be the best thing in the world, the biggest event," he told reporters. "It would be sensational."They never approach drivers to have any input into the design of circuits but I would be very open to help in any way if they are planning to do it, to give advice on curves and corners and parts we should be going through."