Metronet has remained silent on claims that creditors have refused to give it more money to renew the tube.

It is understood that the consortium has run over the cost threshold in its loan agreements and that now banks, led by the European Investment Bank, have declined the group鈥檚 request for a second waiver.

A six-month waiver was granted last September to allow Metronet to continue to draw funds, but now banks are demanding details of cost-cutting plans and pressing shareholders to inject fresh cash into the group.

A Metronet spokesman confirmed that the group was in discussion with banks over the future funding of its 30-year contract but declined to comment on whether a second waiver had been declined.

He said: 鈥淣egotiations are tough when significant sums are at stake. We鈥檙e in the middle of a process that will continue for some months and we expect a positive outcome between Metronet and our banks.鈥�