A government update on the project yesterday also confirmed that Network Rail needs another £140m for work to integrate Crossrail with the national network.

A ministerial statement on the project said the extra £140m needed is “the result of some station and power upgrade work taking longer than planned.”

The additional cash increases the revised cost of the Crossrail On Network Works integration programme to just under £3bn.

And the main Crossrail budget of £18bn could rise again following delays blamed on Covid-19 disruption

The statement said: “Crossrail Ltd are currently in the process of updating their cost and schedule forecasts in light of their recovery plan, including assessing the impact on their opening schedule and will make a further update on this shortly.”

The project was due to be completed in December 2018 but currently has a scheduled full opening date of mid 2022.

The central section is due to open next summer with all stations now ready to trail services apart from Bonds Street.

Crossrail confirmed last month that it was parting company with main contractor Costain/Skanska joint venture at Bond Street and will oversee the completion of work itself.

The update revealed that total construction spending on Crossrail had hit £14.9bn by the end of May this year since July 2008.