A political row within the government has blown up over Heathrow expansion.
Richmond Park and north Kingston MP Zac Goldsmith said he will not stand as a Conservative MP at the next election if the party supports a third runway at the airport.
He opposes the runway, arguing that the focus should be on improving how Heathrow manages its flight capacity.
But fellow Tory MP Tim Yeo said a third runway was necessary for Britain to remain economically competitive, the BBC reported.
A consultation on UK aviation is due to report back in the summer.
Speaking to the BBC’s Sunday Politics Show, Goldsmith said: “If we were to stand at the next election with a manifesto which includes a third runway, I suspect that a number of what are existing Conservative seats would no longer be Conservative seats in this area.”
Goldsmith, a well-known environmentalist, added: “I wouldn’t stand as a Conservative on that manifesto, it’s just not something I would do.
“I suspect there are others who feel the same way.”
Aviation minister Theresa Villiers said she had concerns about the environmental impact of a third runway and the potential for it to damage people’s quality of life.
“I don’t see any technological solution on the horizon which could see us change our minds,” she said. “I see us opposing a third runway.”
But former environment minister Yeo believes Heathrow needs to expand so the UK has a more globally connected international hub.
“We have to have good links to them if we are to remain competitive,” he said.