By Richard Chidwick
Zac Goldsmith has threatened to quit as an MP before he is even elected.
The Conservative candidate for Richmond says he would force a by-election if his campaign promises are not fulfilled.
Mr Goldmsith, who ran the Ecologist magazine, said he will resign as an MP, if elected, if David Cameron performs a u-turn on Heathrow's third runway, parking charges at Richmond Park and Kingston Hospital's future.
During a Richmond Chamber of Commerce hustings with his opponent, Liberal Democrat MP Susan Kramer, Mr Goldsmith said: "There are various things I have said in this campaign with absolute certainty. I said there will be no Heathrow expansion under our Government, there will be no charges for parking in Richmond Park and Kingston Hospital will be safe.
He added: "If any of those promises are broken I will trigger a by-election and allow people to penalize my party."
The Lib Dems have latched on to his move saying he is 'rattled'. Mr Goldsmith's lead over Ms Kramer has tumbled following a dispute over his 'non-dom' status.
Ms Kramer said: "My opponent expected to win the seat comfortably and is finding it's not so easy. This is a desperate pledge from a very worried man."
Stephen Pound, Labour's candidate for Ealing North, said: "Zac Goldsmith clearly thinks a promise from David Cameron isn't worth the paper it's written on. As the Tories have dropped their manifesto commitment to Cross rail within 48 hours, you can see why he's worried about all the Tories' other pledges."