The High Speed 2 rail link could cost taxpayers almost twice the current estimate of £43 billion, according to research from the Institute of Economic Affairs (IEA).
The institute, which bills itself as a “free-market think-tank”, has produced a report which claims that HS2 could cost up to £80 billion due to lobbying from local authorities seeking links to the HS2 stations and “changes to the route to keep voters on side”.
IEA said that these lobbying efforts, which would be funded by the taxpayer, could add £30 billion to the overall cost of the project on top of an extra £7.5 billion which will be spent on new trains.
It is calling for HS2 to be scrapped with the money saved to be used to cut taxes. The Department for Transport responded to the report by saying the project was “absolutely vital for this country”.
Dr Richard Wellings, author of the IEA report, said: "It’s time the government abandoned its plans to proceed with HS2. The evidence is now overwhelming that this will be unbelievably costly to the taxpayer while delivering incredibly poor value for money.
"It’s shameful that at a time of such financial difficulty for many families the government is caving in to lobbying from businesses, local councils and self-interested politicians more concerned with winning votes than governing in the national interest."
Phase one of the HS2 from London to Birmingham is due to open in 2026, with the full Y-shaped route to Manchester and Leeds to follow in 2032 or 2033.
The DFT said in a statement that HS2 would “generate a return on investment that will continue paying back for generations to come”.
"Without it, the key rail routes connecting London, the Midlands and the North will be overwhelmed," added the DFT.
"HS2 will provide the capacity needed in a way that will generate hundreds of thousands of jobs and billions of pounds worth of economic benefits."
The DFT added that it was committed to “managing the cost within the budget we have set for the project and to securing maximum value for money for the taxpayer”.