Heathrow could become a small business airport if the UK builds a new four-runway hub, London mayor Boris Johnson (pictured) claims.

Questioned by MPs yesterday as he appeared before the Transport Select Committee on what would happen to Heathrow if a new hub was built, Johnson said: “Would Heathrow close? I don’t think Heathrow will continue as it is.

“It might have a great future as a business airport. It will be much smaller than 70 million passengers.

“Heathrow could not be a rival hub, but it could be used by all these plutocrats in their jets. You could imagine that kind of thing continuing to happen.

“But you would have all the development potential of that incredible site. Any jobs lost at Heathrow would be readily found again in the developments that would arise there.”

Johnson said Heathrow could be like a “London City West Airport”, adding that he could envisage a “tech city” on the current site.

The mayor, who supports the building of a new airport, added that the UK would need a six-runway hub by 2050.

Heathrow’s owners would require compensation of around €17.5 billion, if regulators forced the airport to wind down, the mayor’s aviation adviser Daniel Moylan said.

This cost could be mitigated by developing the Heathrow site, as well as running a smaller airport, MPs heard.

Johnson yesterday unveiled what was described as a world-class team of experts to help develop plans for a multi-runway hub airport in the southeast of England.

These include design consultancy Atkins and the architects behind Heathrow Terminal 5.

He said: “It is absolutely imperative that work to progress a new hub airport in the southeast is completed as soon as possible.

“The government has set a timetable that dawdles when dash should be the order of the day.

“That is why I have assembled a mighty team of experts who I have tasked with delivering a fulsome examination of the most realistic solutions to our aviation crisis in the shortest time possible, which I look forward to sharing with the government.”

Around 15 different proposals for a new hub airport in the London area have already been made public. Johnson has consulted on criteria that will be used to evaluate each of those proposals to form a shortlist of options.

That shortlist is expected to be announced within weeks. The team assembled by the mayor will combine their expertise to produce detailed feasibility studies of the shortlisted options that will be submitted to the Davies Commission into UK airport capacity.

Plans so far put forward include a floating airport designed by architects Gensier, another plan known as “Boris Island”, and a proposal for a hub airport on the Isle of Grain designed by Lord Foster.

Meanwhile, Moylan has been meeting Kent MPs to try to persuade them to support plans for an airport in the Thames Estuary.