An influential panel of MPs this week issued a fresh warning over the £50bn High Speed 2 (HS2) rail scheme.
The Commons Public Accounts Committee said the government had failed to prove that the proposed rail link between London and the North was worth its price tag.
“The Department for Transport has yet to present a convincing strategic case for High Speed 2,” said committee chairman Margaret Hodge.
“It has not yet demonstrated that this is the best way to spend £50bn on rail investment in these constrained times, and that the improved connectivity will promote growth in the regions rather than sucking even more activity into London.
The committee urged the government to publish detailed evidence showing why building HS2 is the best way of enabling it to achieving its aims.
It also urged the Department for Transport (DfT) to allocate its contingency allowance to specific risks, and to outline how it would keep tight control of contingency spending.
The committee noted that the DfT had “a shortage of the commercial skills it needs to protect taxpayers’ interests on a programme of the scale of HS2” and ordered the department to set out how it would rectify this.
“The pattern so far has been for costs to spiral - from more than £16bn to £21bn-plus for phase one - and the estimated benefits to dwindle,” said Hodge.
The report adds to sustained recent scrutiny of the project.
Institute of Economic Affairs deputy director Richard Wellings last month warned that the costs and benefits of HS2 did not justify the decision to build it. The committee’s comments also follow similar criticism from the National Audit Office.