Heard the one about Jenson Button and the F1 London grand prix?

Jenson Button has backed the idea of a Formula One race on the streets of London – even though the 34-year-old former world champion would be retired in the unlikely event of it ever taking place.

 The idea of London grand prix, taking in such sights as Big Ben, Buckingham Palace and Trafalgar Square, was first mooted in 2012. It was seen at the time as a publicity stunt by Santander, the sponsors of the British Grand Prix.

But the unlikely scenario moved a step closer on Thursday when the government announced a consultation on closed-road motor sportevents in mainland Britain.

Button said: "When I first saw the plans for a London grand prix I knew they were ambitious, but fantastic. The thought of a race through the capital's streets was only a dream when they initiated the project, but this week's [consultation announcement] brings the idea a step closer to reality.

"When you really picture what it would look like it's truly mind blowing. You could create such a unique grand prix through the streets of London – the roads are naturally very wide and long, so straight-line speeds would be high, and you could create a real blend of corners. When you combine all of that with the world-famous monuments that would feature in the backdrop you can see why it would be an awesome addition to the calendar. The dream has taken a step closer this week, and I'd love to see this amazing concept finally happen."

But the idea of the prime minister, David Cameron, or the London mayor, Boris Johnson, paying Bernie Ecclestone about £40m for the dubious privilege of closing down the city remains fanciful, even though Formula One's chief executive has an astonishing talent for persuading countries to build white elephant stadiums and fork out fortunes for events they do not really need.

The notion was put in perspective by Ben Taylor, director of development and communications at the Motor Sport Association (MSA), who told the Guardian on Thursday: "Silverstone's got a long-term contract to host the British Grand Prix. It's the home of British motor racing. It's invested heavily in its facilities and does a great job hosting the race, so there is no obvious opening in the F1 calendar.

"The logistical challenges of hosting Formula One on the streets of London would be significant. Given the right support in the right places it's not insurmountable, but it's not something that you take on lightly."

But Taylor emphasised that that was not the MSA's main aim. "The push from the MSA about getting this change in legislation is much more aimed at hill climbs, sprints and stage rallies around the country in less traffic-heavy routes than Park Lane and Horse Guards Parade."

Meanwhile, the MSA's acting chief executive, Rob Jones, said: "This is the news British motor sport has been waiting for. It represents a once-in-a-lifetime opportunity to change the landscape of our sport, allowing local communities across the country to host motor sport events and enjoy all the excitement and economic benefit they bring.

"The government's enthusiasm for closed-road motor sport, and its launch of a public consultation, is the culmination of years of hard work behind the scenes. We now have to demonstrate the support that exists for closed-road motor sport around the country."

But London is likely to see Formula E, the new FIA-sanctioned series in which the cars are electrically powered. The ten-race championship is planned to end in the city in May or June next year.