The cost of completing Britain’s HS2 high-speed railway line could spiral by as much as 30 billion pounds ($38 billion), the Financial Times said, citing an internal review.

The entire project will now cost much more than the initial estimate of 56 billion pounds, according to preliminary findings by Allan Cook, the project’s chairman. The final price could rise to between 70 billion pounds and 85 billion pounds, according to two people familiar with the matter that the paper didn’t identify.

The soaring cost is caused by a combination of poor ground conditions found during the surveying work, according to one of the people. The high specification and design to allow trains to run at an ever higher speed than comparable projects have also added to the cost, the person said.

Last month, Boris Johnson told the FT he would launch a review of the rail project if he becomes the next prime minister.

  • The HS2 line is expected to boost capacity on the country’s railways by reducing journey time and adding passenger spaces
  • It has been faced with criticism over multiple delays, poor management and allegations that the parliament was misled on the budget for land purchases