Lilian Greenwood, who chairs the Commons Transport Select Committee, called for Ministers to be upfront about the finances of the £56bn project after reports that the tabling of a crucial bill would take place in 2020, rather than next year.

The Department for Transport (DfT) said it was important the 250mph line between London and several major English cities “takes full account” of Northern Powerhouse Rail, the scheme to boost east-west rail connections. But the reported delay has prompted concerns that HS2 will now not open in Yorkshire in 2033 as previously planned, with leaders saying it was “imperative” the date did not change.

Judith Blake, leader of Leeds City Council and member of the West Yorkshire Combined Authority, said: “Any delay in the process which will deliver HS2 to the North is concerning and it is essential that this does not have a knock-on impact on the timetable for construction or the opening of the eastern leg.

“HS2 will deliver thousands of jobs through the improved connectivity, supply chain opportunities, better skills and regeneration spurred by the project and is critical to delivering the full benefits of other transport investments including Northern Powerhouse Rail and the upgrade of the Trans-Pennine route.

“The experiences of rail passengers across the North this summer have illustrated, once again, the consequences of historic under-investment in our rail network.”

Lilian Greenwood said if true, the latest delay was a “poor start to the new parliamentary year for Transport Secretary [Chris Grayling]”. She said: “It’s yet another potential delay to a large and complex transport infrastructure project and raises further doubts over the Government’s commitment and willingness to invest in the Midlands and the North.

“Ultimately, this project was meant to be the ‘great economic conduit’ for the North and part of the plans to rebalance economic growth in this country. Without HS2 Phase 2b, the potential transformation to connectivity across the Midlands and to the great cities of the North and Scotland will be lost.

“The line is scheduled to open in 2033 and rail passengers, local authorities, MPs and businesses will require reassurance that the timetable will not slip.”

The DfT would not confirm the delay, but said in a statement: “In order to maximise the huge potential of HS2, it is important to make sure it takes full account of the emerging vision for the other transformative project of Northern Powerhouse Rail. Phase 2b of the railway will connect the great cities of the North to boost jobs, housing and economic growth, and remains on track to open in 2033.”

Transport Secretary Chris Grayling announced last summer that the tabling of a bill in Parliament for phase 2b – running from Crewe to Manchester, and Birmingham to Leeds – would take place next year.

Mr Grayling last year sparked fury by cancelling the electrification of the Midland Mainline between Kettering and Sheffield, and a similar scheme between Leeds and Manchester is reported to be in doubt because of cost concerns. Speaking in Yorkshire yesterday, Labour leader Jeremy Corbyn said: “The danger is, that delay will just feed more into the narrative that the North is being starved of investment.”

Worries growing of delays to HS2 in the North