London Underground workers are to vote on strikes in a dispute over pay, terms and conditions.
Members of the Transport Salaried Staffs Association (TSSA) working in jobs including advising passengers in stations and Customer Service Managers are being asked if they want to strike or take other forms of industrial action.
The ballot closes on October 18.
The union said LU has made an offer which would see most grades receive a below inflation pay rise and was freezing most pay ranges, which it claimed raised the possibility of long-term, or indefinite, pay freezes.
TSSA general secretary, Maryam Eslamdoust said: "This situation is wholly of London Underground's making, and our members are highly likely to vote overwhelmingly in favour of strike action and action short of a strike.
"Our intention is to send a strong and clear message to London Underground that significant industrial action is on the cards across the network unless they are prepared to meet our aspirations on pay, as well as dealing positively with all other aspects of our dispute.
"We always prefer negotiating and only move towards a strike as a last resort, but the ball is now firmly in LU's court. Our members are determined to get the deal they deserve - one which meets the cost of living now and in the longer term."
