The F1 chief executive's comments were made on the eve of a media event that took place on Thursday in the British capital organised by Santander, the sponsor of the British grand prix at Silverstone.

That the Spanish bank's imaginary F1 layout for London was being suddenly touted as potentially real was "fantastic news" for the organiser and PR agency Sidhu and Simon, according to a report on the BBC.

The Daily Mail agreed: "Dreamland was exactly where Santander's publicity machine was residing last night."

"Of course it's not going to happen," a senior figure is quoted as saying. "You know that, and so do I. But it makes a great story, doesn't it?"

Some are questioning the timing of Ecclestone's comments, insisting the big news is an ideal smokescreen amid the more serious story about former F1 banker Gerhard Gribkowsky's jailing for bribery.

"Great idea," a reader of the Telegraph commented when contemplating a London grand prix. "Bernie will make sure it goes via Wandsworth Prison so he can watch the race for himself."

Writing in The National, Gary Meenaghan agreed the timing of the news "appears a convenient diversion from a less positive tale."

British F1 legend Sir Stirling Moss also doubts the race will happen.

"I hate saying it but I think it would be (unrealistic)," he said. "I'd love to see it but they have been talking about it since I was racing in the 60s."

The National's Meenaghan continued: "Let's get one thing straight -- London will not be hosting a formula one grand prix.

"Not next year, not the year after, possibly not ever.

"Why? Because there are more obstacles in its way than there are speed bumps on the city's streets."

CNN reported that British motoring association AA is already condemning the event on the basis of London's famous traffic congestion.

"We've seen the huge fuss that has been created by road closures during the Olympics and that is just once in a lifetime -- a London GP would be every year," said a spokesman.

And the Independent newspaper said the Westminster Council has "not been consulted".

Even the soberly objective news wires are deeply sceptical.

"It's nothing more than hypothetical for now," said the Associated Press, adding that the project "is yet to move beyond just an idea and has no official backing from the city".

And Reuters said there are "plenty of reasons to doubt it (the London GP idea) would ever pick up speed and become real".

Jenson Button, who was otherwise on-message for the Santander stunt, had to admit: "I'm not sure you would be able to close down London for a grand prix".

Major UK bookmaker William Hill is offering odds of 1/33 that London will not be hosting a grand prix any time soon.

"We cannot see it happening," a spokesman confirmed.

The foreign media was also not fooled, Autosprint wondering if the idea of a London grand prix is "Verita (the truth) o folklore?"

And even The Times, who had published Ecclestone's original quotes exclusively, admitted there are big hurdles that are yet to be cleared.

"Neither Santander ... nor Mr Ecclestone intend to submit formal proposals", the London newspaper conceded.