HS2 will cost more than five times the amount being spent on an equivalent high-speed rail line in France, a group of transport experts has claimed.
The academics said there were “much less costly and environmentally damaging” ways of boosting capacity on the rail network.
They have published a report stating that the project will only provide “limited improvements” in connectivity.
It described the wider economic benefits to the north as uncertain, and said the scheme would contribute nothing to reducing carbon emissions from transport.
The study, led by Prof Tony May from Leeds University and the transport consultant Jonathan Tyler, found that the TGV line from Tours to Bordeaux, currently under construction in France, was costing £20m per kilometre, compared to £105m/km for HS2.
It explained that the higher cost for HS2 was partly due to the need for extensive tunnelling in the Chilterns and the “complex plan” to develop London Euston.
But HS2 Ltd, the company behind the planned link between London and the north, dismissed the comparison with France.
A spokesman said: “The French section of track is not comparable.
The French track has no new stations, it does not go through a dense built-up urban area, it does not have the tunnels that we are building on HS2 to protect the environment, and property prices are very low in comparison to the UK.
“The net result is that it is cheaper, but we will use joint ventures including continental firms with experience of building high-speed rail and this will drive down our costs.”
The academics say a “much fuller range of options” should have been considered to meet the objectives of HS2.
These include alternative routes better integrated with the existing network, enhancements at lower speed and investment in the north.
The report concludes that a review should be carried out to consider these options “objectively, transparently and dispassionately”.
HS2 Ltd responded to the report by saying the scheme would have “significantly less” carbon emissions than cars and planes, while the speed of the trains meant it was designed to be compatible with future technological innovations.
The first phase of HS2 is expected to be completed by around 2026 and will reduce journey times between London and Birmingham by 32 minutes.
A second Y-shaped phase, taking the line to north-east and north-west England and beyond, is due to be completed by around 2032-33.
