Boris Johnson has said he is still opposed to expansion of Heathrow, despite the Conservatives pledging to expand the airport in their manifesto.

The Foreign Secretary told LBC radio that Heathrow expansion was “the wrong solution” given the problems with noise, traffic and air pollution.

But this puts him at odds with his party’s manifesto, with Theresa May having pledged to continue with Heathrow expansion in the Conservatives’ flagship policy document.

Mr Johnson has been a vocal critic of expanding Heathrow as both London mayor and now as an MP, where he represents a constituency in west London near the airport.

When asked about Heathrow expansion, Mr Johnson told LBC: “The position is the one I’ve been arguing as mayor and as Foreign Secretary, and that remains unchanged.

“I think it is the wrong solution and I think particularly the noise and the vehicular and air pollution difficulties will be very difficult indeed.”

Mr Johnson has advocated building a new island airport in the Thames estuary east of London.

Last October, after years of delay, the Government said that building a third runway at Heathrow was its preferred option for expanding airport capacity.

Conservative former MP Zac Goldsmith resigned his Richmond seat last year in protest at the decision to go ahead with the project.

He fought the by-election this triggered as an independent and lost to the Lib Dem candidate though he is standing again in next month’s General Election as the official Tory candidate.