Department for Transport figures have revealed that around £900,000 was spent on a study commissioned by prime minister Boris Johnson on his plans to build a fixed link between Scotland and Northern Ireland.
The doomed project was roundly criticised as implausible when Mr Johnson first mooted it and has prompted even more anger now the feasibility study into the fixed link has been revealed to have cost £896,681.
Conducted by Network Rail chair Sir Peter Hendy, the investigation found that a bridge would cost £335bn, while a tunnel would require a budget of about £209bn.
Prime minister Johnson estimated a cost of around £15bn for a bridge crossing.
Mr Hendy's report concluded that the project 'would be impossible to justify' as 'the benefits could not possibly outweigh the costs'.
The project would be complicated by Beaufort’s dyke – an underwater trench lying on the most direct route between Scotland and Northern Ireland, which would need to be surveyed because around 1 million tonnes of unexploded munitions were being dumped there between the first world war and the 1970s.
Mr Johnson accepted the conclusion of the report, which was carried out alongside a wider review of connectivity in the UK. The entire UK connectivity report cost £1,102,525.
The DfT said the costs for both reviews related to consultancy fees and department staff.
Louise Haigh, Labour’s shadow transport secretary, said: 'There is a cost of living crisis and the prime minister blew nearly £1m on an utterly infeasible vanity project. That’s enough to fill 18,000 potholes. 'This just shows the Tories’ sheer disrespect for public money.'
Mr Johnson has a history of questionable transport decisions dating back to his time as London mayor including more than £50m wasted on plans for a Thames Garden Bridge, a pet project of Johnson's which came to nothing.