The delayed Crossrail project is set to receive a £1.4bn bailout package, it has been announced.

The £15bn Elizabeth line – which will stretch 60 miles across London when completed – had originally been set to launch this month, before project bosses pushed the date back to Autumn 2019.

But delays to “core elements” of the line mean it is now unlikely to open by this already-revised date, Transport for London revealed on Monday.

According to a review by auditors KPMG, the hold-up could cost as much as £2bn.

The flagship project will now be bailed out in a £1.4bn financial package agreed by the government and London Mayor Sadiq Khan.

The deal will replace the need for the £350m bailout originally offered by ministers in October.

When finished, the Elizabeth line will increase the capital’s rail capacity by 10%, carrying more than half a million passengers a day. It is also expected to support more than 360,000 new jobs and boost the UK economy by £42bn.

Khan said he had not hidden his “anger and frustration” over the delays. “This has a knock-on consequence of significant additional cost to the project,” he said.

“It has been increasingly clear that the previous Crossrail Ltd leadership painted a far too optimistic picture of the project’s status.”

His comments come on the same day it was revealed that Khan and Transport Secretary Chris Grayling had nominated Tony Meggs to become the new chair of the Crossrail organisation.