Tory pledges to scrap plans for a third runway and invest in high-speed railways instead have today blown the Heathrow expansion debate wide open.

Speaking at the Conservative Party Conference in Birmingham on Monday, shadow transport secretary Theresa Villiers said a new 180mph rail link could offer a viable alternative to short-haul flights.

The £1.3billion line linking London, Birmingham, Manchester and Leeds would cut flights at the airport by 66,000 a year, she added.

"This is one of the hardest decisions we have faced as a party and we will not run away from it," she told delegates. "That's why I can announce this morning that a Conservative government would say no to a third runway at Heathrow." 

Speaking on behalf of Hounslow Council Cllr Barbard Reid, the lead member for aviation, said: “The hundreds of thousands of people who say NO to expansion at Heathrow will welcome this news.

“Our job now is to continue working with people of all political parties to persuade the Government to abandon their increasingly unpopular plans for airport expansion and join the debate about high speed rail.”

The 2M Group of local authorities published its own vision for a new UK high speed rail network in July, designed by civil engineer Colin Elliff.

The 12 year project would be launched in 2015 and a new track would free up the West Coast Mainline for commuter journeys.

Trips from London to Manchester would be cut from 125 minutes to 80 minutes, while those between Manchester and Leeds from 55 minutes to 17 minutes.

John Stewart, the chair of anti-expansion group HACAN ClearSkies, said: It is a bold plan fitting for the 21st Century.

But a BAA spokesman said: "To prioritise one over the other is a false choice and will put Britain's future competitiveness at risk. It is not clear how this proposal will resolve the lack of airport capacity, a problem which must urgently be addressed