London will have to “bear the cost” of a delay to the £15bn Crossrail project, the Department for Transport’s most senior civil servant has said.
In August it was confirmed Crossrail would open in autumn 2019, nine months after its scheduled launch, to allow more time for testing.
Transport for London said it would miss out on £20m in revenue, but the total cost of the delay could be far higher.
The deputy mayor for transport said she was “hopeful” of a joint solution.
Speaking to BBC London, Heidi Alexander said the mayor’s office had carried out “really productive discussions” with the Department for Transport (DfT), Minister for London Jo Johnson, Transport Secretary Chris Grayling and Chancellor Philip Hammond “just yesterday” about Crossrail.
“I am hopeful that we will find a joint solution to the funding of this project,” she added.
However, about an hour later, the DfT’s permanent secretary Bernadette Kelly told the Public Accounts Select Committee that London, which is “ultimately the beneficiary” of Crossrail, would “have to find a way of bearing the cost of this delay”.
She said: “We’ve already made a very significant contribution, and we are now in discussions with TfL about how any further costs should be born.
“But there is an acceptance in TfL that there is an onus on London to ensure that it is bearing a very fair share of these additional costs.”
Europe’s biggest infrastructure project will help ease London’s chronic congestion by connecting major landmarks such as Heathrow Airport and the Canary Wharf business district.
The route, to be known as the Elizabeth Line, had been due to open in December, but will now be launched in autumn 2019 “to ensure a safe and reliable railway”, transport officials said.
It is running almost £600m over budget.
Ms Kelly said DfT, TfL and the capital’s mayor Sadiq Khan were “still working through” how big the cost of the delay will be.