MORE transport chaos could be on the cards as London Underground (LU) workers are set to be balloted for strike action.

Following disputes over new rosters and the use of outside contractors, the Rail Maritime Union (RMT) has said 750 of its maintenance staff will vote in the next few days.

The ballot will close on January 19 and will involve maintenance staff on all lines except for the Piccadilly, Northern and Jubilee.

The RMT has hit out LU, accusing it of disregarding agreements, "bulldozing through" shift patterns and threatening job security.

But LU has asked the RMT to avoid industrial action and go back to talks.

RMT General secretary Bob Crow said: "LU seem to be hell-bent on confrontation by tearing up the signals framework agreement and by unilaterally introducing new working practices which mean they can make people work what hours they like, when they like.

"On top of that, our members' job security is being undermined by the handing over of work to external private contractors which could be done internally."

An LU spokesman said: "London Underground is planning to introduce a roster covering 24 hours a day, seven days a week to ensure planned engineering staff are always available."

The spokesman also accused the RMT of seeking to break agreements and said "meaningful" talks needed to be resumed on the issue.

He said the only outcome of strike action would be lost pay for staff members.