Formula One boss Bernie Ecclestone has wanted to stage a grand prix in central London for years and McLaren's British drivers and former world champions Lewis Hamilton and Jenson Button have helped design a track.

But it's nothing more than hypothetical for now.

The project is yet to move beyond just an idea and has no official backing from the city, but the F1 chief executive said on Thursday a street race around London's iconic sights would still be "magnificent."

"The idea of an F1 street race in London is something I have had for many years," Ecclestone said.

A hypothetical route taking in landmarks like Buckingham Palace, Trafalgar Square, the Houses of Parliament and London Eye was unveiled in a four-minute promotional video in the British capital. The proposed route would also have a start-finish line on the Mall and cars would race through Parliament Square.

"A couple of years ago we came very close to an agreement with the City of Westminster and the mayor's office but we ran into the small problem of cost," Ecclestone said. "A few years back over half a million people turned-up to watch F1 cars parading through the streets of the capital. The public's appetite for a London Grand Prix is huge."

Earlier Thursday, The Times newspaper reported billionaire Ecclestone had offered to pay $54 million to ensure the street race went ahead and said up to 120,000 spectators would be able to watch from grandstands.

Hamilton and Button had been "intensively consulted" in the design of the circuit, organizers said at the launch later, which would have 14 corners, and a 190 mph straight in the run up to Buckingham Palace. But there are no immediate plans for it to replace the British Grand Prix at Silverstone or be added to the F1 calendar.

"I have to say, this is an utterly epic track and would produce the most stunning and compelling Formula One race," Hamilton said.

Teammate Button added: "It is a great hypothetical track to drive, and is as appealing as the reality of the Silverstone circuit."