Building HS2 between London and Birmingham but not extending the line to Manchester will be “very poor value for money”, MPs said.

There are “many uncertainties” in the Government’s assessment that it was better to complete Phase 1 of the project than cancel the whole high-speed railway programme, according to the Commons’ Public Accounts Committee (PAC).

The committee said it is “highly sceptical” that the Department for Transport (DfT) will be able to attract the private investment needed for the planned London terminus at Euston.

The report raises questions about the ramifications of Prime Minister Rishi Sunak’s decision to cancel HS2’s northern section in October last year amid spiralling costs.

HS2 trains were set to call at Oxenholme, Penrith and Carlisle stations which were to become ‘integrated high-speed stations’ where passengers could catch HS2 trains and access the high-speed network to the south.

Mr Sunak confirmed plans to cancel the leg of HS2 from Birmingham to Manchester in his keynote speech at the Conservative Party conference, but said that 'every penny' of the planned £36 billion leg would instead be spent on key infrastructure.

In Cumbria, he promised to ‘upgrade' the energy coast train line linking Carlisle, Workington and Barrow.

The upgrade would 'improve capacity and journey times' on the line, enabling trains every 30 minutes between Carlisle, Workington, and Whitehaven, according to the government.

At the time, Cumberland Council said they were ‘pleased’ to hear of the government’s plans for the energy coast line but slammed the government for the ‘genuinely disappointing’ decision to scrap HS2 north of Birmingham.

The PAC report stated: “HS2 now offers very poor value for money to the taxpayer, and the department and HS2 Ltd do not yet know what it expects the final benefits of the programme to be.

“The department acknowledges that building just Phase 1 will not be value for money because total costs will significantly outweigh benefits.”

However, it noted that the DfT judged that continuing with that section “was value for money”, partly due to avoiding £11 billion of costs that would be incurred from cancellation.

A DfT spokesperson said: “We disagree with the Committee’s assessment. Their estimated cost figure for Phase One also does not reflect our decision to secure private funding for Euston, or the direction not to proceed beyond the Midlands.

“The Permanent Secretary has already written to the Committee chair setting out her assessment on value for money, and we have repeatedly made clear we will continue to deliver HS2 at the lowest reasonable cost, in a way that provides value for taxpayers.”