Who's in the buying queue

But Gatwick, Stansted and even Glasgow airports are very saleable assets. Planning restrictions, green concerns and land availability dictate that airports are a rare commodity, particularly in the South-East.

So once the investment bankers start the sell-off, which will almost certainly not be until next Easter, there will be no shortage of prospective bidders. Here are the possible runners and riders:

Manchester Airports Group: Majority-owned by Manchester city council, with nine surrounding local councils holding 5% stakes, it could be the only British bidder. It also runs East Midlands, Bournemouth and Humberside airports. Chief executive Geoff Muirhead has made it no secret that he is interested in Stansted and Glasgow. It is also said to have sounded out American and British private-equity backers.

Changi Airports International: Owned by the Singapore government, which through its Temasek investment arm already owns several large stakes in British companies including 49.9% of Sir Richard Branson's Virgin Atlantic. "We are open to evaluating the deal," said a spokeswoman.

Fraport: The hugely ambitious operator of Frankfurt airport has long been keen to get into Britain. It also manages Cairo, Delhi and Lima airports. Chief executive Wilhelm Bender said it would "certainly look at what comes up for sale".

Hochtief: Germany's biggest construction company previously said if Gatwick was put for sale it would be "particularly interested". It has investments in Athens, Hamburg, Düsseldorf and Sydney airports alongside private-equity partners.

Global Infrastructure Partners: A joint venture between Credit Suisse and General Electric, which is the majority owner of City Airport.

Macquarie: The Australian bank and infrastructure funder owns Bristol, Sydney, Brussels and Copenhagen airports.