Ministers could be forced to officially concede that HS2 is “low value for money” after the Government abandoned the eastern leg of the controversial rail link.

An official financial assessment signed off by the civil servants concluded that the project met the necessary threshold as value for money if it was built in full.

It said: “While Phase One as a standalone project represents ‘low’ value for money, it is a step to the full HS2 network that contributes to an overall positive of ‘low to medium’ value-for-money position.”

However, Boris Johnson’s decision to axe the £32bn eastern spur to Leeds and Sheffield, part of a wider programme of rail works across in the regions called the Integrated Rail Plan, paves the way for the assessment to be republished.

Tracy Brabin, mayor of West Yorkshire, seized on the Government’s own assessment as evidence that it should reverse its decision.

She said: “Evidence has shown that the HS2 eastern leg as previously planned did have a stronger economic case than the western leg and would provide benefits to the whole HS2 network, therefore improving the overall business case and value for money for the taxpayer.

“The eastern leg would provide transformational economic growth and contribute to rebalancing of the economy, whilst reducing the impact on the environment by reducing car use and freight traffic contributing to decarbonisation. These are all vitally important things that aren’t necessarily reflected in traditional value for money terms.

“There should not have to be a choice between connecting the east or the west of the country though. Alongside other northern leaders, I will continue to make the case for the North and for West Yorkshire, around the need for HS2 delivery in full, as well as delivery of Northern Powerhouse Rail and a crucial stop in central Bradford.”

A government spokesman said: “The Department for Transport has no plans to issue a revised notice to proceed as that was a specific design point on whether to proceed to the main construction stage of Phase 1.

“We periodically undertake Accounting Officer assessments if scope, costs or benefits change on our major projects.

“As the Integrated Rail Plan made clear, further work will be undertaken to determine the best way to get high speed services to Leeds. If its conclusions lead to substantial changes in scope then we would consider updating the Accounting Officer assessment for Phase 1.”