Shadow transport secretary Theresa Villiers said that her party would say no to a third runway at Heathrow, and concentrate instead on high speed rail.
She added: “It will leave a lasting legacy for the future - and it will lay the foundations for a high speed network that I believe will one day stretch across the country.
“We will target construction of the new high speed line to begin in 2015, with full completion by 2027.”
The Conservatives would open a competition to build the new high-speed rail link between London, Birmingham, Manchester and Leeds. Heathrow would also be linked into the main rail network.
A journey from London to Manchester, which takes over two hours on the fastest trains, would take just 80 minutes, while Manchester to Leeds times would come down from 55 minutes to just 17 minutes.
A Conservative government would contribute £1.3 billion a year - in today's money - to the cost of track and land for the high-speed line.
This annual contribution could be met from 2015-27 within current annual levels of Government capital spend on rail, the Tories said.
The Liberal Democrats accused the Conservatives of "hypocrisy", saying that London Mayor Boris Johnson was advocating a new London airport away from Heathrow as the same time as the shadow cabinet was ruling out airport expansion.
Greenpeace and the Campaign for Better Transport welcomed Ms Villiers announcement but airport operator BAA and the Society of British Aerospace Companies expressed dismay.