"The Canary Wharf group is supposed to be LUL's showpiece station group, but managers there are running out of control to the extent that industrial relations have now entirely broken down," RMT general secretary Bob Crow said today.

"New attendance prodecures have been imposed on our members outside existing agreements and without any pretence of negotiation.

"Employment of one RMT member has been medically terminated despite his being passed as fit to return to work by LUL's own occupational health people.

"A female member of staff who was sexually assaulted on the barrier has suffered constant harassment from local management since.

"A gay member of staff has suffered homophobic remarks, and there is a widespread view that gay staff members are routinely discriminated against

"The RMT learner rep for the group has been harassed, along with the workplace colleagues who have supported him, and local management have refused to release the union's health and safety rep to undertake her duties.

"Local Jubilee Line managers are failing to comply with agreed flexible working arrangements, and are repeatedly telling staff that they have no need of union reps to attend meetings.

"Each of these problems is unacceptable, but taken together they are an appalling catalogue of harassment and victimisation that must be stopped.

"Repeated attempts to resolve these issues have proved fruitless and the RMT executive has agreed that the only option left is to ballot the more than 80 members concerned for industrial action," Bob Crow said.