LABOUR is preparing to dump its commitment to a high-speed rail line from London to the edge of Liverpool – because of delays to hugely expensive schemes in the capital.

Maria Eagle, the party's transport spokeswoman and the MP for Garston and Halewood, revealed she was considering cheaper ways to tackle overcrowding and cut journey times.

A Conservative source described the rethink as "political suicide" for Labour, adding: "Is Labour really going to oppose a measure that we support, to improve the North?”

Key projects in London – the Crossrail and Thameslink schemes – would have already begun by 2015, the likely date of the next election, and would have to be completed first, she warned. But Ms Eagle insisted Labour was not abandoning passengers in Liverpool and the North, adding: "There will be other options to tackle overcrowding that we will examine in our policy review."

And she accused David Cameron of exaggerating his Government's commitment to high-speed rail, because its Bill will only include planning and legal powers to take the line to Birmingham.

Before its election defeat, Labour had promised legislation to allow 250mph trains to run as far as Manchester and Leeds.

Under those plans, trains would slow to conventional speed just south of Manchester, but would still slash London-Liverpool journey times from 2hrs 10mins to 1hr 36mins.

Labour's rethink shatters the cross-party consensus that high-speed lines are essential, a consensus long seen as vital to private-sector confidence the project will be carried through.