Zac Goldsmith today claimed Heathrow Airport will only be expanded if environmental tests are “rigged”.
The Conservative Mayoral candidate said expansion at the UK’s busiest airport was now “off the agenda”.
Ministers last month decided to delay a final decision until at least next summer "subject to further consideration on environmental impacts and the best possible mitigation measures".
Critics claimed the move was aimed at protecting Mr Goldsmith, who threatened to resign as an MP if the government backed the third runway, during his campaign to succeed Boris Johnson in the capital.
Asked if he would resign if he became Mayor and Heathrow was given the go-ahead, he replied: "No, of course not."
Mr Goldsmith told BBC radio: "Heathrow cannot pass the air pollution test unless the test is rigged.
"If Heathrow passes the air pollution test and is given a green light, that could only mean that the test has been set in such a way that Heathrow was always going to pass it," he added.
"I'm not not trusting anyone, I think Heathrow is off the agenda, I think we have won this campaign.
"The only way that Heathrow can be given the green light now is if the test is rigged."
But Back Heathrow campaign director Rob Gray said Mr Goldsmith's claim was "outrageous".
Mr Goldsmith, a leading Eurosceptic, said he would vote to come out of the European Union if David Cameron failed to deliver "meaningful" reform in Britain's relationship with Brussels.
The Tory MP for Richmond Park insisted he was "not a headbanger" on the issue and wanted to give the Prime Minister a "chance" to deliver reforms.
"If the reforms are not meaningful, if they are not radical, if it doesn't mean that we will have a more decentralised, more democratic union then, of course, I will vote to come out because that would be in the national interest."
