The cost of building HS2 could hit £66 billion, according to a progress report published by the Department for Transport.
HS2 Ltd estimated the cost of the high-speed rail project would be £54 to £66 billion when the company updated its board in June, the report says.
This is up from the last estimate for phase one – £49 to £57 billion – from November 2023.
The overall spend to date – which includes spending on phase one and the now-scrapped phase two – is £32.8 billion.
The costs and forecast costs are in 2019 prices and do not account for inflation since.
New chief executive Mark Wild is carrying out a review of HS2’s cost and timetable.
Transport Secretary Heidi Alexander said the latest cost estimate does not take into account “reset work” the Government has commissioned since July.
Nor does it consider the private financing the Government has committed to securing to extend the Birmingham to London leg to Euston, she said.
In the Budget, Chancellor Rachel Reeves confirmed funding to build a pair of tunnels stretching 4.5 miles between Old Oak Common – in the western suburbs of the capital – and Euston.
The Government is seeking private investment to redevelop Euston station for the new line and expand the underground station.
It is the first progress report to be published since Labour came to Government.
The chair of HS2 Ltd said on Tuesday he would be standing down after almost four years.
Sir Jon Thompson will leave the role in the spring and the search for a replacement will begin soon.
A Department for Transport spokesperson said: “These estimates are out of date and don’t take into account the urgent measures this Government took to get the project back under control or the previous government’s decision to cancel Phase 2 and attempt to secure private funding for Euston.
“The Transport Secretary has asked HS2 to urgently provide updated and clearer estimates of the project as soon as possible, and we have made it the number one priority of the new chief executive to drive costs down.”
A spokesperson for HS2 Ltd said: “Mark Wild joined as our new CEO this month and clearly recognises the programme’s serious cost challenges.
“He is now leading a comprehensive review of HS2’s cost and schedule which will report into Government next year and lead to a full reset of the project.
“HS2 will lay the foundations for improving our rail network – connecting our two biggest cities with fast and reliable journeys while freeing up the existing track for more local services – but clearly changes in delivery are needed to ensure it realises its full potential.”
