Plans to change HS2 train size could reduce capacity and speed in north, says expert

HS2’s planned trains would not be able to tilt like the Pendolino (pictured), which runs on conventional tracks in the north of England. Photograph: Dave Porter/Alamy

Plans to change the size of HS2 trains to maximise capacity are likely to inflate costs and mean fewer seats and slower services north of Birmingham, a senior government and rail industry figure has warned.

The £2bn order for 54 high-speed trains, to be built in Britain by a joint venture of Alstom and Hitachi, is under review as HS2 Ltd seeks to cut costs and renegotiate contracts.