Parliament’s Public Accounts Committee says that a fixation on a delivery deadline of last December led to warning signs that the programme was in trouble being either missed or ignored.

The Department for Transport is urged to explain to the Committee the steps being taken to encourage a culture of “openness and transparency” across its major programmes both internally and within its delivery bodies, so that project completion dates can more easily be revised in future.

Disappointment is also expressed by the Committee at the DfT and Crossrail Ltd’s “unacceptably laissez-faire attitude to costs potentially rising by nearly £3Bn”. The Committee added it is not satisfied by the Department’s “vague response to our questioning on how it protected taxpayers’ money” when overseeing delivery of the programme.

Governance arrangements on Crossrail have also been found to be “weak” and characterised by “a catalogue of failures to adequately oversee performance”.

The Committee also says that DfT and Crossrail have been unwilling to accept their responsibilities for delays and cost over runs on the programme. It adds that “it is unacceptable that the Department and Crossrail Ltd are unable to identify the root causes of the programme unravelling so quickly and so disastrously”.

Public Accounts Committee chair Meg Hillier said: “It is clear that the delivery deadline of December 2018 had been unrealistic for some time. But the Department for Transport, Transport for London and Crossrail Ltd continued to put a positive face on the programme long after mounting evidence should have prompted changes.

“Wishful thinking is no basis for spending public money and there remain serious risks to delivering this programme, with a revised schedule and costings for completing the work still to be agreed. Some £2.8Bn of extra funding has been provided for Crossrail but even that may not be enough.”

She also said that it is unacceptable that Parliament and the public still do not know the root causes of the failures that beset this project. “Accountability in the use of public money is of fundamental importance,” Meg Hillier added.

A DfT spokesman said that as soon as delays were identified the Department and TfL “acted swiftly to identify lessons, change the leadership of the Crossrail Ltd Board, and strengthen governance and oversight.

“It is deeply disappointing that the Public Accounts Committee – which previously described the oversight of Crossrail as a ‘textbook example’ of governance – has not recognised any of the steps that have been taken to ensure delivery of this vital project while protecting taxpayers.”

The spokesman added that the DfT “absolutely rejects” the claim that the Department adopted a ‘laissez-faire’ attitude.

Crossrail chief executive Mark Wild added: “We take the views of the Public Accounts Committee very seriously and will be reviewing their recommendations carefully.”

He added that since becoming chief executive last November he has overseen an intensive review of the programme. Progress is being made and an “enhanced governance structure and new leadership team” have been put in place to strengthen the programme.

(Photograph: Crossrail)