Andrew Tyrie wrote a furious letter to transport secretary Chris Grayling earlier this week, noting it would be the fifth time he had posed questions on the economic case to support the Davis Commission conclusion of a new runway at Heathrow.
“Failure to answer them will lead people either to conclude that this work has not been done – in which case it would be unacceptable for a decision to be made without the evidence to support it – or that it has been done, and gives answers that do not necessarily support the conclusions of the Davis report,” he wrote.
And on HS2, the Treasury Committee chair said that while government support for the project is couched in terms of an economic case, “the numbers do not support such an argument”.
“HS2 has the weakest economic case of all the projects within the infrastructure programme, yet it is being pushed through the with the most enthusiasm,” Tyrie said.
“The case for providing sufficient detail to enable other ways of improving rail capacity – including at lower speed – to be fully assessed, remains very strong.”
The department for transport did not respond to request for comment.