The committee says it is now “increasingly alarmed” about stalled progress at the London terminus, with the Department for Transport yet to take a decision on the design and construction approach for the station.

The past 15 months have been spent looking for cost saving options including the potential for a smaller station, says the committee which was told by High Speed 2 that it is “getting close to the point where the programme will literally run out of time” if a decision is not made soon.

Old Oak Common is currently being set as the London terminus for when the new high speed railway first opens to decouple it from the risks at Euston. “The development of Euston is a real challenge that must be resolved swiftly now,” said committee chair Dame Meg Hillier.

She added: “HS2 is already one of the single most expensive taxpayer funded programmes in the UK but there’s actually no clear end in sight in terms of the final cost, or even the final route. The project was plagued by a lack of planning and transparency from the start and there are many difficulties ahead.”

The report adds that Government still needs to decide how Phase 2b – the northern sections of the route – will integrate with other parts of the railway and transport system.

It also says cost increases which have seen the scheme’s original budget of £55.7Bn rise to a current estimated range of between £72Bn and £98Bn have dented public confidence.

In addition, the report speaks of growing concerns that the Department for Transport and project company ‘do not yet know how they will turn the benefits promised from High Speed 2 into a reality’, including what additional investments will be needed or how these will be funded.

A Department for Transport spokesman said: “We are making significant progress delivering HS2; we welcome the committee acknowledging that progress and our renewed commitment to transparency.   

“The Integrated Rail Plan will soon outline exactly how major rail projects, including HS2 phase 2b, will work together to deliver the reliable train services that passengers across the North and Midlands need and deserve.”

Meanwhile, the Government has today agreed to establish a new rail board for Wales, with responsibilities set to include the development of proposals for priority rail enhancements in the country.

This follows a recommendation by the Welsh Affairs Committee which published an inquiry into rail infrastructure in Wales in July. The board will meet for the first time later this year and will comprise director level representation from Welsh Government, Department for Transport, Transport for Wales, Network Rail and train operators.

Welcoming the decision, Welsh Affairs Committee chair Stephen Crabb said: “We heard from numerous witnesses during our inquiry that more coordination is needed to drive investment and improvements, and I hope the board will deliver this. It’s also very welcome the speed in which they will start convening, and I hope people across Wales will start feeling the benefits feed through to their railway journeys.”

(Image: High Speed 2 Ltd)