The cost of HS2 could rise to as much as £66bn according to latest estimates presented to the Department for Transport.

The latest budget came as it was confirmed that current HS2 chairman Sir Jon Thompson will step down from his role next Spring after four years on the board.

Latest figures show £32.8bn has been spent on the project so far with the current estimate for completion at between £54bn-£66bn.

The Goverment is desperate to drive that figure down and expects the next revised budget to be lower.

It said: “The Transport Secretary has asked HS2 Ltd to provide updated and assured estimates of the project as soon as possible and we have made it the number one priority of the new Chief Executive after safety to drive costs down.”

New Transport Secretary Heidi Alexander said: “Since coming into government, we announced urgent measures to get a grip on HS2’s costs and ensure taxpayers’ money is put to good use and we will be working closely with the new CEO, Mark Wild, to deliver the remaining work as cost effectively as possible, including setting a realistic budget and schedule.”