Union leaders today claimed that the "privatisation disaster" of London Underground was about to be killed off under moves to bring the Tube upgrade back under public control.
Transport for London (TfL) is expected to buy out shareholders that control Tube Lines, the private sector consortium responsible for the Jubilee, Northern and Piccadilly lines, with a deal expected within days.
Details of the surprise move emerged as the General Election drama was unfolding. It is likely to involve Tube Lines shareholders being paid hundreds of millions of pounds.
The company's contracts and 2,500 staff are expected to be taken over by TfL, bringing an end to the £30 billion Public Private Partnership (PPP), promoted by Gordon Brown when he was Chancellor, under which large sections of the Tube were sold off on 30 years leases.
Bob Crow, general secretary of the Rail Maritime and Transport union, said: "If the reports are true that Tube Lines is at last being taken back under public control it would be a welcome development and would kill off the privatisation disaster on the Tube once and for all.
"Rather than finding out about such an important development through leaks to the press, staff and passengers are entitled to hear it direct from Mayor Boris Johnson himself.
"This will be a recognition on a massive scale that transport privatisation does not work and RMT's campaign to roll out the renationalisation of the rail network will continue regardless of who forms the next government."
A TfL spokesman said: "TfL continues to work closely with Tube Lines and its shareholders, Amey (Ferrovial) and Bechtel, to explore all options to address the issues outlined by the PPP Arbiter.
"The parties are yet to reach any conclusion, but we remain committed to working with Tube Lines and its shareholders to identify the best way of providing the vital improvements the Tube needs."
The expected takeover follows the collapse of Metronet, the maintenance giant responsible for two-thirds of the Tube, whose staff now work for TfL.