The demand for HS2 has 'likely been overestimated' and the £33 billion project does not offer value for money - according to a report out today.
The New Economics Foundation says evidence that the rail line, which will run through the Midlands, will promote economic growth or tackle the north-south divide, is limited.
The report also claims the line will be 'carbon intensive and environmentally damaging', and recommends the money earmarked for the project be spent elsewhere, ideally on transport systems away from the Capital.
The Government is firmly backing plans for the route which it says will boost the economy and is needed for the country to remain competitive.
An influential group of MPs says the DfT has failed to present 'a convincing strategic case' for HS2.
Campaigners say they hope to put plans for HS2 through the Midlands back to square one as they prepare to go to the High Court tomorrow.
Campaigners from HS2 Action Alliance are heading to London tomorrow to take on the Government at the Court of Appeal.