By Georgie Keate
A Tory MP has threatened to trigger another by-election in a marginal seat if the government reneges on its promise to oppose a third runway at Heathrow.
Environmentalist Zac Goldsmith, whose constituency Richmond Park lies right under the flight path, said he was commitment to sticking to his mandate.
“I promised before the election that if the Conservatives perform a U-turn on Heathrow, I would trigger an immediate by-election so that local voters can have their say,” he told the Daily Telegraph.
“I also said that I would not stand as a Conservative if the Conservatives allow room for a third runway in their next manifesto.”
Goldsmith's seat was only won by a narrow margin from the Lib Dems in 2010 and could easily switch hands again if a by-election was called.
The MP's statement comes amid a renewed focus on the UK's aviation policy as commentators speculate on whether the government will decide to put the runway decision into the hands of an independent commission.
Amid the rumours circulating over the Cabinet reshuffle, transport secretary Justine Greening last week said she would reconsider her position if the government began supporting the third runway.
However, environment committee chair, Tim Yeo, came out last week in support of the third runway at Heathrow and George Osborne has refused to rule the possibility out.
A spokesperson for the prime minister said the Coalition's position opposing the runway had not changed and a consultation would be announced in the next few weeks.
"There are strong views about this issue on both sides of the argument. Any process must involve listening to those views and, therefore, I would expect all the options to be considered within that process," he said.
"There's a coalition programme for government that sets out the position on that, but I think there is going to be a debate about this issue and I would expect the people in favour of that proposal to put forward that proposal."