The government needs to speed up the HS2 project and stop talking about how much it costs, an influential committee of MPs said today.
The Commons transport committee said ministers should consider building the second phase northern section of the project at the same time as the initial London-Birmingham link.
It also suggested the government emphasise that costs may only hit £28 billion rather than £50 billion.
"The Department for Transport's (DfT's) communications about HS2 should emphasise that the estimated cost is £28bn, not £50bn, and that cost increases to date have largely been due to the decision to undertake more tunnelling and other work to mitigate the impact of the project on people living near the route," the report said.
"The project is now commonly regarded as costing £50bn and rising. This has led to exaggerated references to HS2 requiring a 'blank cheque' from government."
The cost of the project is likely to be £42.6 billion, which includes £14.56 billion for contingencies.
The mention of the 'blank cheque' argument is a veiled reference to Labour's policy position, which has seen the party waver in its support for the project.
U-turning on HS2 would allow Labour to cost a variety of policies ahead of the general election but could prove embarrassing given it was originally a Labour proposal.
A critical conference speech by Ed Balls suggested the party had already turned its back on HS2 but recent comments from the shadow transport secretary indicated that Labour was sticking with it for now.
The call for a change in the nature of the debate around HS2 comes as polling shows opposition to the project remains stubbornly high.
A YouGov survey from October showed 53% of people oppose the scheme and just 27% support it.
MPs said their support for the project was "not unqualified" and they raised concerns about KPMG research which suggested the train line would raise £15 billion a year for the British economy by 2037.
"The DfT's [Department for Transport] written evidence clearly identifies the limitations with KPMG's research, referring to 'challenging' forecasts and 'uncertain' results," the report found.
"However, we are convinced that it is essential for the UK for HS2 to go ahead, and to do so as a project which has the backing of all three major political parties."
Opponents of HS2 said the MPs failed to speak to critics of the plan, unlike similar hearings by the public accounts committee and the Treasury committee.