HS2 trains will run slower than planned to save money, Transport Secretary Heidi Alexander is set to announce.
The Press Association understands the Cabinet minister will tell the Commons on Tuesday that the maximum speed of services will be 320km/h (199mph), down from the original design of 360km/h (224mph).
Services will still be faster than Japan’s bullet trains, which reach up to 285km/h (177mph).
A major review to be published following the announcement is expected to find that “gold plating” HS2, including by focusing on achieving the “highest possible speeds”, is among the faults that contributed to the project’s woes.
Sir Stephen Lovegrove, the former national security adviser, will criticise the “original sins” in the decision-making behind the scheme.
Ms Alexander is set to reveal a new target cost of the project, which will be below £100 billion.
Constructing the high-speed line from London to Birmingham – plus the now abandoned onward legs to Leeds and Manchester – was initially estimated to cost £32.7 billion (in 2011 prices), but the budget has spiralled.
In January 2024, HS2 Ltd’s then-executive chairman Sir Jon Thompson said the estimated cost of building HS2 between the capital and Birmingham had reached as much as £66.6 billion (in prices at that time).
The Transport Secretary will also set out a new schedule for when HS2 will open, after previously confirming it was not possible for the latest target window of 2029 to 2033 to be met.
The first phase of the railway was originally planned to launch in 2026.
A Government source said: “The Lovegrove Report further confirms the astonishing extent to which previous Conservative governments had totally lost control of HS2, frittering billions of taxpayers’ money away and leaving the project no closer to being finished than when it started.
“It has been a sorry mess, but this Government has done the hard yards to pull the project out of the dirt and deliver the better connections that have long been promised to the Midlands.
“Britain has the talent and capability to build big infrastructure projects. The Transport Secretary will harness that as she turns the project around.”
The Financial Times reported that Labour ministers commissioned an internal review into whether scrapping the entire project would be better value for money than continuing with it.
This found that abandoning the scheme – which has already cost an estimated £40 billion – would cost at least as much as completing it.
HS2 Ltd Mark Wild warned Jo Shanmugalingam, permanent secretary at the Department for Transport, that cancelling a programme of the scale of HS2 is “unprecedented in the Western world”.
He wrote in a letter: “Our collective assessment of the current legal position is that land should be fully remediated, which would include demolishing all built assets, and returning land to the same condition as prior to construction to allow it to be potentially sold back to its original owners where appropriate.”
He added: “There is little evidence that removing these assets would cost much less than creating them.”
