The latest numbers were unveiled by Transport Secretary Heidi Alexander as she also confirmed the opening of the full route between London Euston to Birmingham Curzon Street and to the connection to the West Coast Main Line at Handsacre Junction will not happen until “between May 2040 and December 2043.”

Top speeds on the route will also be reduced to cut costs.

HS2 CEO Mark Wild has been working on rescoping the project including a complete cancellation which was dismissed due to an estimated remediation cost of £58bn for work completed so far.

Alexander said: “The reset work also makes clear that progress on finishing the civil engineering for the entire line of route is at least four years behind the original schedule, and that the time required to test and commission HS2 to ensure a reliable and safe service was underestimated by another three years.

“The number of years left to complete the programme is roughly the same as when construction started in 2020, and it is likely we will need to spend the same amount as has already been spent to date.

“It is now imperative that we proceed with the final stages of the HS2 reset so that the programme is brought under control and delivered sensibly going forward.

“Under new leadership, HS2 Ltd is putting construction back in logical order, strengthening commercial controls, restructuring the organisation, and rebuilding the partnership with government.

“HS2 Ltd’s new management team inherited a challenging commercial position. Prior to the reset, commercial capabilities and the management of HS2’s construction contracts were not effective.

“HS2 Ltd’s ability to settle commercial matters progressively and contemporaneously had deteriorated and become insufficient over recent years. Consequently, large backlogs had been allowed to develop in relation to cost verification, cost finalisation and contract change.

“HS2 Ltd has since concentrated on strengthening its commercial controls. New commercial roles have been created to focus on cost verification and contract management, to scrutinise every payment application, to challenge contractor claims, and to manage contracts in taxpayers’ interests. These improvements must be fully embedded in the company, and endure beyond completion of the reset, to the conclusion of the programme.

“HS2 Ltd is also engaging with its key supply chain partners to review contracts, close out historic payments only where appropriate and justified, and seek opportunities to incentivise improved performance. This work will be critical to stabilising costs and enabling us to make the spend on HS2 as efficient as possible.”