The first stage of a planned high-speed rail link which could cut journey times from Yorkshire to London to 80 minutes has been branded a "white elephant" by a public spending pressure group.
The Taxpayers' Alliance said HS2, a scheme to run 200mph trains between London and Birmingham, would cost 17bn and yet would only benefit a minority of rail passengers.
Ministers have announced plans to start building the link within five years and to eventually extend it through South Yorkshire and Leeds – a move that transport bosses believe would bring a 62bn boost to the region's economy.
But rail expert Chris Stokes, in a report produced for the Taxpayers' Alliance, said the business case for the London-to-Birmingham scheme "had not been made" as it would neither produce a financial return nor cut greenhouse gas emissions.
"The Department for Transport have promised before that they wouldn't justify major new capital investment on the basis of overly optimistic projections for demand, but they have done exactly that in this case," he added.
"The need for new capacity can be better served with longer and more frequent trains on the existing quick InterCity service, which wouldn't need anything like the same subsidy. HS2 should be cancelled."
Taxpayers' Alliance director Matthew Sinclair said the Government should focus on making commuter journeys more convenient and affordable rather than "a flashy new train set that will be a huge white elephant".
"Passengers on the new high-speed line are never expected to pay enough to cover the project's costs in fares and it will depend on massive subsidy at the expense of millions who never use the line," he said. "This just can't be a priority with the massive scale of the fiscal crisis and huge pressure on family budgets."
RAC Foundation director Professor Stephen Glaister, said: "In austere times one must really question whether it is wise to spend 17bn to allow the wealthy to travel quicker between Birmingham and London, whilst cutting many transport services with greater and more widespread public benefits. Increasingly, the evidence, as underlined by this report, shows it's not."
The Government's plan is for a Y-shaped high-speed network, heading north from London to Birmingham and, following the Yorkshire Post's Fast Track to Yorkshire Campaign, branching into an East Coast line through South Yorkshire and Leeds and a West Coast line through Manchester.
The Department for Transport and the Association of Train Operating Companies said high-speed trains would generate economic benefits and meet growing demand for rail travel.
"Intercity rail travel has risen sharply in recent years. Already some of our key rail arteries are close to capacity, so doing nothing is simply not an option," a Government spokesman said.
"To duck this issue now would consign Britain to steadily deteriorating travel times and conditions between our major cities."