The Elizabeth line, as it will be known once services begin, will link Reading and Heathrow airport, west of the capital, with Shenfield in Essex and Abbey Wood in southeast London.
Trains are planned to run every 2½ minutes each way through a central core between Paddington and Whitechapel, with intermediate stops at Bond Street, Tottenham Court Road, Farringdon and Liverpool Street.
It is intended to boost rail capacity in the capital by 10 per cent, cut journey times and relieve congestion on the existing infrastructure – particularly the Central line of the London Underground. The line will also boost revenue for Transport for London (TfL).
The body responsible for delivering it is Crossrail Ltd, a wholly owned subsidiary of TfL.
But the project is running about two years late. Tottenham Court Road is the most of advanced of the 10 new stations, but will not be completed until August or September 2019, while Bond Street may not be finished before spring 2021.
The latest Public Accounts Committee report is scathing about the management of the project, saying: “Given the scale and complexity of the remaining work, it is staggering that Crossrail Ltd continued to believe until as late as July 2018 that the central section of the railway would open in December 2018.
“This over-optimism which was prevalent throughout has proved hugely damaging to the programme.
“Given the amount of work still to be done, it is clear that Crossrail Ltd did not have a full appreciation of the scale and complexity of the outstanding work until recently, particularly the work to bring together all the infrastructure and systems required for the railway to begin operations.
“Commuters have been let down by a programme that is well behind schedule and has seen costs escalate far beyond what was originally planned.”
The current budget is £17.6bn, 19 per cent more than originally estimated, with no certainty about the final bill.
The committee points out that Crossrail Ltd continued to pay its executives bonuses, even as the programme was going off track. The former chief executive, Andrew Wolstenholme, was paid a bonus of £481,000 for performance in 2015-16 and £160,000 for 2016-17.
Mr Wolstenholme has been replaced as chief executive by Mark Wild, while the former chair, Sir Terry Morgan, has been replaced by Tony Meggs.
Crossrail Ltd said: “Following a detailed audit of the programme, including what went wrong in the past, the new team has produced a robust and realistic plan to put Europe’s most ambitious and complex infrastructure project back on track.
“As many risks and uncertainties remain in the development and testing of the train and signalling systems, Crossrail Ltd has identified a six-month delivery window with a midpoint at the end of 2020. Crossrail will be making every effort to deliver the service as early as possible.
“The central section of the Elizabeth line will open between Paddington and Abbey Wood and link the West End, the City of London, Canary Wharf and southeast London with initially 12 trains per hour during the peak.
“It is expected that all stations on the route will open except for Bond Street which is delayed because of design and delivery challenges.”
The PAC also takes the Department for Transport (DfT) to task, saying: “We have witnessed cost increases and delays on major rail projects several times over the past few years and the department still does not appear to have got a grip on the problem.
“Until the department properly embeds the lessons learned from the programme, we remain sceptical about its ability to oversee major rail projects.”
A DfT spokesperson said: “The department consistently challenged the leadership of Crossrail Ltd on the delivery of the project.
“When problems became clear the department acted swiftly and effectively, changing the leadership of the board and strengthening governance structures.
“The new Crossrail Ltd management team has now produced a new plan to open the railway, and the department and TfL will continue to scrutinise progress to ensure this happens as soon as possible.”