A new report published this morning by the Public Accounts Committee blasts Network Rail and the Government for significant failings in the design, planning and cost-estimating of the programme.

These have cast doubt about Network Rail’s management of future projects.

Network Rail’s estimated cost of the Great Western Railway track upgrade rose by £1.2bn to £2.8bn in the space of a year.

The report doubts whether this project can even now be delivered to the revised target and budget.

The spending watchdog has now called for an urgent review  — not just on the different sections of the Great Western route, but also on the Midland Main Line and TransPennine electrification routes.

The committee is demanding that Network Rail improve its ability to produce realistic cost estimates and make sure that robust and detailed plans are in place for infrastructure projects before starting construction.

Meg Hillier MP, Chair of the PAC, said: “Mismanagement of the Great Western programme has hit taxpayers hard and left many people angry and frustrated.

“This is a stark example of how not to run a major project, from flawed planning at the earliest stage to weak accountability and what remain serious questions about the reasons for embarking on the work in the first place.

“The sums of public money wasted are appalling—not least the £330 million additional costs the Department for Transport will have to pay to keep the trains running because of delays to electrification.”

She added that the Department for Transport failed to adequately challenge Network Rail’s plans to carry out the infrastructure work and questioned whether electrification work on this and other lines was even necessary.

“Government accepts it got this project badly wrong and must now demonstrate it has learned the lessons.

“Network Rail admits there are still very significant risks in the Great Western scheme and it is vital these are fully identified and carefully managed.

“It must work with the Department to ensure this information is properly factored into the whole rail modernisation programme.

“For its part, the Department should urgently review its plans for electrification—not just on the different sections of the Great Western route, but also on the Midland Main Line and TransPennine routes.”