MPs are expected to vote today on whether to release funds so the government can begin spending on the controversial HS2 rail project.
The remaining stages of the high speed rail (preparation) bill are currently being debated in the Commons.
The initial funds would pay for surveys and property to begin development, and to compensate evicted residents whose homes lay on the proposed route.
The vote is of particular significance, as prime minister David Cameron and Sir David Higgins – the chairman of the project – have both said that the project must be backed by all three major parties if it is to work.
Some Conservative MPs are expected to rebel and vote against the plans, while there is uncertainty over Labour’s support.
Twenty-one Tory backbenchers voted in favour of scrapping the project when the bill last entered the Commons.
Labour first proposed HS2, but senior figures have expressed concern over rising projected costs. Shadow chancellor Ed Balls said last month that there would be “no blank cheque” for HS2 if he became chancellor.
“The question is not just whether a new high speed line is a good idea or a bad idea, but whether it is the best way to spend £50bn for the future of our country,” he added.
However, Sky News has reported that inside sources say that many Labour backbenchers have criticised Balls’ approach. They say that at a Labour transport committee, 17 Labour MPs spoke out in support of HS2. Only two spoke against.
Labour is expected to support the project in today’s vote, but there is only a single-line whip. This means Labour MPs will not be punished if they vote against the project.
The Liberal Democrats support the project, while deputy prime minister Nick Clegg has accused Labour of a “betrayal” of northern England.
The rail line would connect London to the West Midlands by 2026, and be developed to include Leeds and Manchester by 2033.
It has been criticised both because of the impact it might have on the countryside, but especially for its cost, which was estimated to have risen from £34 billion to more than £50 billion by the free market thinktank the IEA.
On Tuesday, a report by the Department of Transport downgraded the potential profits of the project. The benefit-cost ratio has been downgraded to 2.3, meaning that for every £1 spent on the project it will get a £2.30 return. This is a decrease on the £2.50 originally predicted.
However, the department argued that HS2 is still a necessity, The report suggested that alternative options would cause “14 years of gridlock, hellish journeys and rail replacement buses”.
Transport secretary Patrick McLoughlin, said, “We need a radical solution and HS2 is it. A patch and mend job will not do – the only option is a new north south railway.”