Tube Lines loses claim against London Underground

But an independent adjudication ruled that London Underground were not to blame for the overrunning engineering works on the Jubilee and Northern lines, despite Tube Lines claim it was not given sufficient weekend closures to get the job done.

The Jubilee line upgrade is now likely to finish late this year, with further weekend line closures possible until the autumn. The upgrade work was originally scheduled to be finished at the end of last year.

London Underground managing director Richard Parry said: "We welcome this ruling by the independent adjudicator, which makes it clear that Tube Lines is responsible, in full, for the costs it has incurred as a result of delays to the upgrade of the Jubilee and Northern lines."

A Tube Lines spokeswoman said the company would be reviewing the adjudication before making any further comment.

It has been a difficult few months for the Canary Wharf-based consortium. Apart from the overrunning works, Tube Lines is also awaiting the final decision on its next tranche of funding for upgrade work from the end of this year to 2018.

It has asked for £5.75billion but the Public Private Partnership arbiter has indicated it should do the work for £4.4billion. The arbiter's final decision is due in April.