Construction on Crossrail is due to start in 2010

They supported without a vote or motion, allowing debate on the Crossrail Bill to continue after next month's Queen's Speech.

But Junior transport minister Tom Harris told MPs there would be "no curtailing" of debate when it returns.

The rail link will connect Maidenhead, Berkshire in the west to Essex, through the centre of London.

Mr Harris said: "There will be no curtailing of scrutiny in the next session."

We back Crossrail in principle...that was our position [and] it remains our position Stephen Hammond, Tory MP

"Whatever outstanding reservations members may have about elements of the project, I do not believe that anyone wants to see the Bill infinitely delayed."

Last month, Prime Minister Gordon Brown said the project was one of "enormous importance, not just for London but for the whole country".

He said it would generate an additional 30,000 jobs and help retain London's position as the world's pre-eminent financial centre.

'Congested arteries'

For the Tories, Stephen Hammond said: "There is a deal now in place and the deal will need some examination and still some more clarity.

"We back Crossrail in principle...that was our position, it remains our position and will be our position."

Liberal Democrat Tom Brake said he wanted reassurances on the exact breakdown of the �16bn figure, which he said the government had not yet provided.

But he said: "Crossrail is desperately needed in London.

"It is going to provide the heart bypass operation that London's transport system needs and provide another transport route so that people don't have to rely on those heavily congested arteries."

'Persuasive' argument

Reading MPs, Labour's Martin Salter and Tory Robert Wilson both argued the project's western terminus should be in the town.

Transport minister Tom Harris said the argument for extending Crossrail to Reading was "persuasive" but the Bill would not be altered by the government at this late stage.

Construction of the route is expected to start in 2010 with trains running from about 2017.

It will provide 24 trains an hour into the heart of London from the east and west, improving rail links to the West End, the City and Docklands.