The rail minister has insisted that the government is "absolutely committed" to delivering HS2 trains from London to Manchester and to the east of England.
However Huw Merriman added "cost pressures" must be examined as he faced calls from Labour to "categorically deny" the Department for Transport is working on plans to "slash" the high-speed rail project.
Phase One of HS2 involves the railway being built between London and Birmingham, with the line extended from the West Midlands to Crewe in Phase 2a.
