Union leaders have warned that a strike by nearly 1,400 workers at failed London Underground contractor Metronet is “all but inevitable” after last-minute peace talks broke down today.

A meeting with the administrators in charge of the Metronet consortium failed to quell a mounting dispute over job security, working conditions and pensions.

The RMT union told Times Online that barring any U-turn before a 6pm deadline, a series of strike dates will be announced tomorrow.

A walkout could severely affect services on the Tube. The staff carry out vital maintenance and repair work on nine London Underground lines including the Circle, Victoria and Central lines.

An RMT spokesman said: “The talks appear to have failed and a strike is all but inevitable.”

Union leaders are seeking guarantees that jobs will be secure if and when Metronet’s Public Private partnership contracts are awarded to another private sector firm.

Metronet collapsed last month after running an estimated £2 billion over budget. Allan Bloom, a partner at Ernst & Young, was appointed as the administrator.

Its management had begun consultation on up to 500 redundancies and the transfer of another 200 staff to Bombardier, the engineering firm and one of Metronet's five former shareholders.

Jennie Bremner, assistant general secretary of Unite, which also has members on the Metronet workforce, said: "It was clear from the outset that the administrator was not going to consider our position whatsoever.

“The administrator seems to be intent on continuing Metronet's failed policies which led to the company being taking into administration in the first place.”

“Our hand has been forced and we now have no other alternative but to set dates for industrial action."

Ernst & Young said the unions' threat was "completely unhelpful". A spokeswoman said: "We feel it is in the interests of all parties to avoid major disruption to London and any financial damage to Metronet."

A Transport for London spokesman said he was “disappointed” by the move. “Our priority is to get Metronet out of administration and a strike will not help that process.”

Times Recommends

• Lies and cover-up at MG Rover exposed by report
• High oil prices push manufacturing costs up
• Primark founder steps down as chief executive