MPs will launch a probe today into the planned multibillion-pound overhaul of the crumbling Palace of Westminster amid concerns about the huge costs.
Commons Treasury committee chairman Andrew Tyrie said that insufficient evidence had been produced to justify the restoration plan, which could cost up to £4 billion.
Under the proposals set out in a feasibility report by experts, including consultants Deloitte, MPs and peers would have to move out of their familiar home while the work — expected to last five to eight years — is carried out.
Mr Tyrie said that among the options his committee would be looking at was whether both the Lords and Commons needed to “decant” from the palace at the same time, or whether the work could be done over a longer period with less disruption.
“Neither the report by Deloitte nor that by the joint commission provides enough of the evidence needed to come even to a preliminary decision on these proposals,” said Mr Tyrie.
“So the Treasury committee will attempt to collect some of it. This is why the committee has called for evidence on this massive, and hugely expensive, restoration project.