There is “overwhelming evidence” that the costs of HS2 are “out of control” and its benefits overstated, the deputy chair of its review panel has said.
Lord Berkeley said the high-speed rail line, linking London and northern England, is likely to cost over £108bn.
A vocal critic of HS2, the Labour peer said he believed MPs had been “misled” about the price – set at £55bn in 2015.
He has published a “dissenting report” on the project, but the government said it represented his personal view.
Trains are due to start running on HS2 between London and Birmingham in 2029.
However, Lord Berkeley says there is little prospect of that before 2031, and warns high-speed trains will not reach Manchester and Leeds until 2040.
Lord Berkeley was the deputy chairman of the independent Oakervee Review in to HS2, set up by the government.
However, he has withdrawn his backing from the review, which is expected to be published in the coming months.
He says he disagrees with a draft version of its official report and as a result has published his own version.
He said he and other members of the panel were prevented from contributing to the final draft of the government-commissioned report because the review was “effectively terminated” on 31 October.
Updates from the Cannock Chase Radio News Desk via BBC Stoke and Staffordshire