The cost of building HS2 between London and Birmingham is likely to soar to nearly £67bn at today’s prices.

The new estimate provided by HS2 chief Sir Jon Thompson is nearly double what the entire project was expected to cost in 2013.

Then the whole project, including the earlier planned phase two routes to both Manchester and Leeds, had a price tag of £37.5bn.

Giving evidence to the Transport Select Committee, Sir Jon confirmed that HS2 Ltd’s latest estimate for the London to Birmingham stretch is between £49bn and £56.6bn in 2019 prices.

This is above the government’s present target for the project to be delivered at £45bn.

He estimated after three years of industry-wide rampant cost inflation in steel and concrete in particular around £8bn-£10bn should be added to the estimate to get an indication of the true cost at today’s prices.