The Crossrail project which is aimed at improving transport links from Reading, Twyford and Maidenhead to London has received yet another setback
A report by the Commons' Public Accounts Committee (PAC) stated that the estimated cost of completing London's new east-west railway exceeds current available funding by £150 million.
The project will improve transport links from Reading, Twyford and Maidenhead to London.
The predicted cost of finishing the project is now £18.9 billion. Crossrail says it's been hit by a number of problems including construction delays.
Crossrail says the fall in passenger numbers has had a severe impact.
Labour MP, Dame Meg Hillier who chairs the PAC, said: "We are finally, thankfully seeing a clearer sense of ownership, responsibility and determination to complete the Crossrail programme from those in charge, but there remains a serious £150 million funding gap to finish the programme.
"There must be a focus now on finding real solutions to this.
"With fares down because of the ongoing impact of Covid, we also need more clarity on the plans and timescale for repaying the significant Government loans."
The committee also expressed doubts over how and when Transport for London (TfL) and the Greater London Authority will repay taxpayer loans issued for the project amid the collapse in fares revenue due to the coronavirus pandemic.
The railway will be known as the Elizabeth Line once it opens, with services running from Reading and Heathrow in the west to Shenfield and Abbey Wood in the east, via central London.
Trains are now due to begin running in the central section between February and June next year, with full services scheduled to launch in either December 2022 or May 2023.
The new Elizabeth Line is not expected to open until next year.
TfL commissioner, Andy Byford, said: "While I understand that everyone wants to know the specific opening date for the Elizabeth line, this will not be confirmed until we are completely satisfied that we are ready to go.
"The project has my full, personal attention, the opening window continues to be what I have always said, namely the first half of 2022 and the final cost will not exceed a penny more than the budget which TfL inherited when it assumed full control of the project under my direction."