Proposals for expansion at Birmingham Airport have been shunned as a third runway at Heathrow moved a step closer after a Government-appointed commission revealed its expansion options.
In an interim report, the Airports Commission, headed by former Financial Services Authority chief Sir Howard Davies, also put an extra, second, runway at Gatwick airport in West Sussex on to its short list.
In addition, Sir Howard's team kept the door open for a Thames Estuary airport scheme, favoured by London mayor Boris Johnson, with the commission saying it will look further at the Isle of Grain airport option in the first half of next year.
But the commission has not shortlisted proposals for expansion at Birmingham Airport, which spelled out plans for a massive expansion including a second runway and a capacity of 70 million.
The commission said it had concluded "there is a need for one net additional runway to be in operation in the South East by 2030".
It added that its analysis also indicated "that there is likely to be a demand case for a second additional runway to be operational by 2050".
Sir Howard's team said it would be taking forward for further detailed study proposals for new runways at two locations:
:: Gatwick: Gatwick Airport Ltd's proposal for a new runway to the south of the existing runway;
:: Heathrow (two options): Heathrow Airport Ltd's proposal for one new 3,500-metre (11,500ft) runway to the north west and Heathrow Hub's proposal to extend the existing northern runway to at least 6,000 metres (20,000ft), enabling the extended runway to operate as two independent runways.
The commission said it had not shortlisted any of the Thames Estuary options "because there are too many uncertainties and challenges surrounding them at this stage".
It said it would undertake further study of the Isle of Grain option in the first half of 2014 and "will reach a view later next year on whether that option offers a credible proposal for consideration alongside the other shortlisted options".
Sir Howard's team also said that there was likely to be a case for considering Stansted and Birmingham as potential options for any second new runway by 2050.
There are no firm long-term proposals in the commission's interim report. Those will come when the commission makes its final report in the summer of 2015 - after the next general election.
The last Labour government supported a third runway at Heathrow but expansion at the west London airport was ruled out by the coalition Government when it took power in May 2010.
Last week, Tory MP Zac Goldsmith said any decision by the Prime Minister to back Heathrow expansion would represent an "off-the-scale betrayal" and David Cameron would "never be forgiven in west London".
Transport Secretary Patrick McLoughlin has said the coalition's pledge was not to build a third runway "in this parliament" and stressed that any decision would come after summer 2015.
Launching the report, Sir Howard said: "Decisions on airport capacity are important national strategic choices and must be based upon the best evidence available.
"The commission has undertaken a fresh, comprehensive and transparent study of the issues. This report is the product of extensive consultation, independent analysis and careful consideration by the commissioners."
He went on: "The UK enjoys excellent connectivity today. The capacity challenge is not yet critical but it will become so if no action is taken soon and our analysis clearly supports the provision of one net additional runway by 2030.
"In the meantime, we encourage the Government to act on our recommendations to make the best of our existing capacity.
"The commission will now focus on the challenge of appraising the three options, further assessing the case for a new airport in the Thames Estuary, and delivering a robust final recommendation to Government in summer 2015."
The interim report was welcomed by bosses of Heathrow and Gatwick, with Stansted's owners saying they were pleased that the airport was being considered for expansion after 2030.
While the Stop Stansted Expansion group was thrilled the Essex airport was left off the immediate short list, the Gatwick Area Conservation Campaign greeted news of Gatwick's appearance on the short list with dismay.
Medway Council in Kent was also unhappy that the Thames Estuary plan had not been ruled out.
Mr Johnson said: "It is clear that Gatwick is not being considered as a hub airport, meaning a second runway there would only provide temporary relief to Heathrow.
"And that means Sir Howard has effectively told the Government it has two choices - proceed with the creation of a monstrous Heathrow... or proceed with the construction of a new hub in the inner estuary that can be built for the same cost as a four-runway Heathrow, and would bring new jobs, homes, and long-term competitiveness.
"A new airport in the inner estuary is the only credible hub option left, and the only one that would uphold this country's claim to be the natural financial, commercial and economic capital of Europe. By keeping it on the table, Davies is saying you have a choice - between a damaging U-turn or a radical new vision for expansion.
"We will be fighting the former and hailing the latter, and I'd urge the Prime Minister and the leader of the Opposition to do the same."