Union leaders are locked in last-minute talks to try to avert strikes on the Underground, due to start tomorrow. The RMT Union said Tube Lines maintenance staff will walk out for two days from 7pm on June 23. The strike would cause widespread disruption

Union leaders are locked in last-minute talks to try to avert strikes on the Underground, due to start tomorrow.

The RMT Union said Tube Lines maintenance staff will walk out for two days from 7pm on June 23.

The strike would cause widespread disruption on the three lines maintained by the private contractor, Jubilee, Picadilly and Northern.

RMT general secretary Bob Crow said: "It is clear that if we cannot reach agreement over the Tube Lines dispute around jobs, pay and conditions that it will have a major impact and that there's a real danger that Tube officials will take serious risks with safety to try and run trains."

Also on Wednesday, RMT members from Serco Docklands, which operates the DLR, will walk out for three days from 4am.

The Rail union said it was considering a new offer from Tube Lines and talks were ongoing at Acas over the DLR dispute.