Another extra financing package worth more than £2bn was agreed on Monday afternoon as Crossrail chiefs admitted they couldn’t guarantee hitting the revised opening date of Autumn 2019.

The network was originally due to open this week after being heralded for years by the previous management team as “on time and on budget.”

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

Crossrail first admitted this summer that the project had bust its original £14.8bn budget by £590m and was running late.

The revised total cost of the project is now £17.6bn.

The latest financing package has been agreed by the Mayor of London, the Greater London Authority and Transport for London.

It comes as an independent review by KPMG into financing and governance on the project nears completion.

It revealed an estimated £1.3bn to £1.7bn shortfall in funding to complete the project plus the need for an extra £750m contingency fund.

New Crossrail chief executive Mark Wild also confirmed that “having reviewed the work still required to complete the project, an Autumn 2019 opening date could no longer be committed to at this stage.”

It was revealed that “core elements of the infrastructure being delivered by Crossrail Ltd, including the stations and the fit out of the tunnels, are at varying stages of completion and more funding is therefore required to complete it, as well as the extensive safety and reliability testing needed for the new railway systems.”

Mayor Khan said: “I haven’t hidden my anger and frustration about the Crossrail project being delayed. This has a knock-on consequence of significant additional cost to the project.

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

“I have ordered the release of all Crossrail Board minutes in the last five years to provide transparency to Londoners on their decision making, and working with the DfT, brought in a new leadership team.”

Tony Meggs will become the new Chair of Crossrail Ltd replacing Sir Terry Morgan who resigned last week.

Meggs, who will step down from his role as CEO of the Infrastructure and Projects Authority (IPA), will oversee the final stages of delivering the Crossrail project.

The Crossrail Ltd Board will be further strengthened with the nomination of former MP Nick Raynsford as Deputy Chair.

Mike Brown, London’s Transport Commissioner, said: “Crossrail Ltd’s announcement of the delay to the Elizabeth line is extremely disappointing and, only now, is the scale of what is yet to be completed becoming clear.

“The confirmation of this funding agreement will now allow Crossrail Ltd and its new leadership to focus on finishing the remaining construction work on the stations and tunnels and then completing the vital safety testing in order to open the railway for passengers as quickly as possible.

Mark Wild, Chief Executive, Crossrail Ltd, said: “Since I joined Crossrail Ltd in November I have been reviewing the work still required to complete the core stations and rail infrastructure and begin the critical safety testing.

“It is evident that there is a huge amount still to do. Stations are in varying stages of completion and we need time to test the complex railway systems. This means that I cannot at this stage commit to an autumn 2019 opening date.

“My team and I are working to establish a robust and deliverable schedule in order to give Londoners a credible plan to open the railway and provide a safe and reliable service.

“Once that work is completed we will then be in a position to confirm a new opening date.”