Poll finds majority backing for third Heathrow runway These included new runways at Heathrow, Gatwick or Stansted - all of which have been ruled out during the current Parliament by the Coalition Agreement. Should Sir Howard back a third Heathrow runway, he will find himself at odds with Mr Johnson and a number of Tory MPs underneath the flight path, including Angie Bray, Mary Macleod, Justine Greening, the former Transport Secretary and Zac Goldsmith, who has threatened to trigger a by-election if the Government changes its policy. Privately several Tory MPs have voiced fears that a change of policy could cost the party dear in the next election. The London Mayor's opposition to a third runway, which could put him at odds with the Tory hierarchy at the next election, showed no sign of weakening as he condemned the Davies inquiry for even considering it. The runway was, he said, "a complete disaster" and "simply will not happen." But Sir Howard tried to avoid getting drawn into the row. I observe the political debate swirling around this, but I don't think it makes sense to get involved in it "We have been told that all options, including the third runway, are on the table, and for the moment that is where they shall remain," he told the Observer.