Ex-Chancellor Alistair Darling has warned of a potential “nightmare” on England’s existing railways if the multibillion-pound HS2 line is built.
He was in the cabinet when the high-speed rail scheme was approved in principle but has now changed his mind.
Mr Darling told the BBC the rise in projected costs from £32bn to £42.6bn would drain cash from other lines.
Labour’s front bench backs the scheme, which ministers say is vital and will create billions of pounds of benefits.
The first phase of the scheme would see 250mph trains running on a new railway line to be built between London and the West Midlands by 2026. A second phase would see the line extended further north with branches to Leeds and Manchester by 2033.
‘Falling apart’
Mr Darling, who was also transport secretary in the previous Labour government, was chancellor when the first stage of HS2 was approved in principle in 2010.
He told the BBC that at the time he thought the case for HS2 was “just about stateable”. But he had since changed his mind because of the revised costs – which he said meant future governments would not have the money to spend on other lines.