The government should consider building the northern and southern sections of High Speed 2 at the same time, according to MPs.
The House of Commons Transport Committee said that the economic case for building the line from north to south has strengthened since its last report.
It now suggests that incoming HS2 chairman Sir David Higgins should examine options for building the two phases concurrently, and report to ministers by the end of 2014.
A change in the construction schedule could lead to high speed trains running north of Birmingham far earlier than currently envisaged in 2032/33.
Transport committee chair Louise Ellman said: “We raised this issue initially when we first looked at the scheme two years ago, and at that time the government did tell us it couldn’t be done.
“We don’t think that’s good enough. This is about benefiting the whole of the country.”
Pinsent Masons transport partner Patrick Twist said: “The committee’s suggestion that the two phases should be built simultaneously makes a lot of sense, but there are two factors which mean this will be difficult to implement.
“The first question is whether the construction industry actually has the capacity in terms of resources and manpower to undertake the whole project in one go – that could probably be sorted with careful planning but the other constraint is financing.
“HM Treasury would not support any rescheduling which would result in the whole spend being concertinaed into a much shorter period.”
The report reasserted the committee’s view that HS2 is vital for securing sufficient capacity in Britain’s railways. It also encouraged the government to emphasise that the estimated cost of the project is £28bn, not the £50bn that has been reported.
The committee also said that while it remained convinced of the economic benefits to UK regions of building the line, the government should recognise the limitations of research published by KPMG in September. The study, which found that building HS2 could lead to a £15bn boost to UK GDP, has received some criticism for its methodology.