The government faces a straight choice between a “horror option” of expanding Heathrow, or building a new hub airport in the Thames estuary.

Responding in detail to the Airports Commission interim report, London mayor Boris Johnson was typically outspoken, reportedly calling in prime minister David Cameron to stop “pussyfooting and fannying around” over airport expansion, according to the Daily Telegraph.

Johnson agreed that his team will work alongside the commission to provide further “conclusive evidence” that plans for an inner estuary airport should be taken forward, even though it was missing from the short-list of three preferred options put forward.

As Gatwick and Heathrow were highlighted for expansion, Johnson appeared to suggest that ministers had told commission chairman Sir Howard Davies to “have another think” and not totally discount his favoured option of a new hub airport in the Thames estuary.

A further study into building a hub airport on the Isle of Grain in north Kent – one of the proposals backed by Johnson – will be carried out in the first half of 2014.

“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,” said Johnson.

“And that means he has effectively told the government it has two choices – proceed with the creation of a monstrous Heathrow, on a constrained site that won’t solve our capacity crisis, but would inflict untold misery on hundreds of thousands more Londoners through the din of many more jet engines in parts of the capital and home counties that have not so far experienced it; 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, deputy prime minister and the leader of the opposition to do the same.”

Johnson went on to tell the Parliamentary Press Gallery: “It is pretty obvious to me what is going on.

“I think the reality is that Sir Howard started with a short list that did not include much except Heathrow and I think he has been told to have another think.”

He said that Heathrow is “the wrong way forward for the country” and pledged to fight on to win support for his Thames estuary airport scheme.

“The sooner we get a clear answer from the Government, in my view, the better,” said Johnson. “We can’t keep pussyfooting and fannying around forever.”

He added: “Everybody in my party and indeed in several other parties, so far as I can remember, were elected on a manifesto to oppose a third runway at Heathrow.

“That happens to be the correct policy. Why change it? Why dump it? The sooner we get back to that, the better.”

Zac Goldsmith, Conservative MP for Richmond upon Thames, has suggested he could quit the party if the government supports expansion of Heathrow.

He questioned Sir Howard’s independence and told the Telegraph: “If my party changes its position on Heathrow expansion – the ‘no ifs, no buts, there will be no third runway’ position – if that changes, then yes, I’m obliged to trigger a by-election.”

Sir Howard rejected any suggestions that his commission had been influenced by ministers.

He said: “We have talked to a lot of people and people offered their views, this is a perfectly normal process in the course of producing a report of this kind, but the decisions are ours and made by us alone.”