Metronet’s administrators have approached private bidders to raise interest in the failed PPP.

At a London Assembly transport committee meeting, administrator Alan Bloom said the firm’s bankers had approached “a number of companies in the marketplace”.

London Underground (LU) is expected to make a formal offer to buy Metronet out of administration, and bring its maintenance contracts back under public sector control.

Tim O’Toole, LU managing director, said: “If we got hold of Metronet, we’d get these contracts restructured and that would be saleable. We could break it up and put the station upgrades out to somebody and the track upgrades to someone else.”

It emerged that Metronet owes £1.6bn in secured debt.