- 8 updates
Plans for High Speed 2 took a blow today as they were attacked on both financial and environmental grounds.
A report by the Institute for Economic Affairs suggested that the cost of the project is likely to double official estimates, reaching £80 billion.
The charity Campaign for Rural England also said it believes half a million people - including some living 40 miles from the planned route - would be affected by the construction.
But the chief executive of HS2, Alison Munro, described the claimw as "absurd" and insisted the project would remain within budget.
ITV News correspondent Lewis Vaughan Jones reports:
The chief executive of High Speed 2, Alison Munro, has said that new data on the number of people that will be affected by the rail project are based on a "worst case" scenario.
She said she expected to minimise the number of lorries travelling to and from the construction project by re-using 95% of the material that is excavated.
The chief executive of High Speed 2, Alison Munro, has dismissed the claim that the rail project will cost £80 billion - more than double the official estimate - as "absurd".
She told ITV News that she "doesn't recognise" the figure allegedly quoted in a report by the Institute of Economic Affairs, and that she is confident the cost will not overrun.
A Department for Transport spokesman said the Government were "committed to managing the cost" of HS2 after a report suggested the project had doubled in cost to at least £80 billion.
The estimated cost of building the controversial High Speed 2 rail network, which will travel through parts of Buckinghamshire and Northamptonshire has doubled to at least £80 billion, The Sunday Telegraph has reported.
A 58-page independent report by the Institute of Economic Affairs, due out tomorrow, will say that the spiralling cost of construction means HS2 now "defies economic logic" and should be cancelled.
The institute's report also apparently claims the £80 billion cost of HS2 could create "£320 billion of economic value" if it were invested in road, rail or other transport projects instead.
"All construction access routes" have been considered as part of plans for the HS2 rail route, a project spokesman has told the Mail on Sunday, in response to campaigners' claims of widespread disruption.
He said the public had been consulted on the matter and offered the chance to "express potential concerns or suggest alternatives" and would continue to be involved.
The construction of the HS2 rail project will affect the lives of more than half a million people across Middle England, campaigners have said, including those living up to 25 miles from the controversial train route.
They say towns along a 40 mile wide corridor through Oxfordshire, Buckinghamshire and Warwickshire will be affected by the millions of extra lorry journeys during the building process.
The estimations by the Campaign for the Protection of Rural England (CPRE) come from analysis of information it requested from the HS2 project.
Campaigner Ralph Smyth condemned HS2 for its reluctance to hand over the information, saying: "It is not acceptable that it took a charity to uncover this."