The High Speed 2 rail project has won the support of MPs on the Transport Committee.
But the committee wants a re-examination of the planned construction schedule of the £42.6 billion project to look at “the case for building the line from north-to-south, as well as from London northwards”.
Currently the plan is to build from Euston in London to Birmingham in the first phase of HS2, due to open in 2026, and then further northwards to Manchester and Leeds in the second stage of development to be completed by 2032.
Louise Ellman (pictured), the committee’s chairman, said: “We support the strategic case for HS2 published recently by the government.
“Having looked at this, and at new research by KPMG that examined the project’s possible regional economic benefits, we remain confident that construction of a new high-speed line is the only way to deliver the step change in capacity on the West Coast mainline needed to accommodate long-term demand for both passengers and rail freight.”
Ellman added that building the HS2 line “concurrently” in each direction from both London and the north should be considered.
The committee also warned that the government should not fund HS2 by cutting spending on other forms of transport.
“We would not accept a situation in which other vital transport projects were delayed because of HS2’s funding requirements and we remain concerned about how refinements - for example to incorporate a stop for Heathrow into the plans for phase 1 - may have an impact on the budget,” added Ellman.