Her remarks are made in a wide ranging letter, prompted by an announcement at the end of August that Crossrail will no longer open in December. She also wants to see a monthly update provided to her committee on progress with the project, from now until its completion.

Caroline Pidgeon writes that the delay to Crossrail “came as a huge shock”, given repeated assurances that the scheme was on schedule. “We are determined that the failures in governance and transparency at Crossrail must end immediately and cannot be replicated in future infrastructure projects” the letter says.

On the point of transparency, Caroline Pidgeon said that “the tendency to take controversial items into private board sessions must end”. She cites one case in January where the Transport for London Board was apparently told of an electrical explosion, only for the public discussion to be curtailed and the meeting to resume in a private session.

The minutes, she went on, make only vague reference to this news “despite the fact this is now considered the point at which the delivery schedule began to unravel”.

Caroline also points to a public meeting on 25 July which suggested that the project was on schedule, only for cameras to be turned off “for the ‘real’ discussion where bad news is shared”. She welcomed a “long public discussion on the delay” on 19 September, but also claims that the TfL Board held several private sessions about Crossrail that same day to discuss the revised delivery schedule and capital funding requirements away from public view.

An explanation given that this was due to the sensitive nature of discussions was dismissed by Caroline as “simple not an acceptable reason for secrecy”.

The committee chair also calls for full details to be shared of three independent reviews into remaining construction activity, testing and trial operations, and governance of Crossrail.

In addition, she calls for monthly updates from Crossrail to her committee on progress until the end of the project, further detailed information from TfL on the revenue impact of the delay, details of any penalty clauses from those to have provided funding and details of revised opening dates.

A spokesman for the Mayor of London said Sadiq Khan has “expressed his frustrations directly to the leadership of Crossrail, both privately and during meetings in public” about the delay to opening the central section of the project.

On the call for greater transparency, the Mayor’s office said that aspects of the Crossrail programme and finances are commercially sensitive and relate to the performance of contractors. “It is standard common practice for commercially sensitive parts of meetings to be held in private,” a spokesman said, adding that “project updates are given in public session, given the Mayor’s strong desire for transparency around the project”.

TaxPayers’ Alliance campaign manager James Price said: “Taxpayers deserve to know the problems facing projects that their money is being spent on, and who is to blame for those problems. This disgraceful culture of mendacity has to end. Those calling for this are completely right to fight for transparency and accountability.”

Image credit: Crossrail