The Financial Times has reported that the department is seeking more savings on the high speed rail project less than a year after the Leeds leg was scrapped.

But with Northern leaders having now waited nearly 12 months for the first signs of a promised £100m study, pressure is rising on the Prime Minister to deliver.

Henri Murison, chief executive of the Northern Powerhouse Partnership, termed the briefing as "selective" to "damage" HS2, and said focus should be centred on progress.

Passengers board trains at Leeds train station.

"The current amount of funding for HS2 Phase 1, £44.6bn, should be sufficient," he insisted.

“I am more concerned that the study promised to work out how to get HS2 trains to Leeds hasn’t started yet, a year after the Integrated Rail Plan (IRP) promised it.”

Construction began on the first phase of HS2 between London and Birmingham in 2020.

The FT, citing internal review documents, said the Treasury has asked to identify potential cuts or "scope reductions" to the full project as the first phase runs "many billions" over.

Mayor of West Yorkshire Tracy Brabin at a meeting of the Transport for the North Board after the Government confirmed the eastern leg of HS2 was being scrapped while the planned Northern Powerhouse Rail (NPR) project was being curtailed. Danny Lawson/PA Wire

The Government has insisted works are underway and within budget, while contracts and scope are "routinely considered" to deliver the best value for taxpayers.

The Government faced significant controversy as it appeared to scale back plans for the high-speed railway line last November, with the eastern leg of HS2 now set to end at East Midlands Parkway rather than taking in parts of Yorkshire.

Trains would then run on an existing line to Sheffield, it outlined, with £100m to be spent instead on a study to “look at the most effective way to run HS2 trains to Leeds”.

In July, then Transport Secretary Grant Shapps assured The Y orkshire Post that passengers will one day “see HS2 trains rolling into Leeds”, with analysis to begin "very shortly".

But the launch of the study - delayed after the Treasury reportedly questioned the cost - is yet to begin nearly a year after it was promised. Northern leaders are waiting for the terms of reference to be published by Transport Secretary Anne-Marie Trevelyan.

Further questions remain over North Powerhouse Rail (NPR), with Boris Johnson's Government cutting Bradford from its route, but Liz Truss since pledging that high-speed trains will stop at a new station in the city with plans to be detailed "in due course".

Despite concerns over delays, Mr Murison said: "In Anne-Marie (Trevelyan) we have a northern Transport Secretary who was overwhelmingly positive about HS2, whilst the PM has committed to get the linked Northern Powerhouse Rail line to Bradford. The incoming Chancellor, Jeremy Hunt, has been a longstanding backer of HS2 .

"Thanks to the last weeks of disruptive fiscal policy the capital budget in this spending review period will be tough; but the costs of HS2 are spread over decades, so savings not hitting today's budgets, and making short term cuts would throw away the benefits of all the investment to date.

“Proportionately, even after the £36bn cuts were made, the remaining IRP mostly committed the Government to future spending – only a small fraction of costs for the new across the-Pennines or the remaining HS2 line south from Manchester fall in the coming few years.”

Frustrations mount over delays to promised study on bringing HS2 trains to Leeds