London Underground workers will start voting on Tuesday on whether to take strike action over pay.
The Rail, Maritime and Transport union (RMT) said it is unhappy at the latest pay offer from London Underground, calling for improved staff travel facilities for all Tube workers.
The union has criticised the freezing of pay bands, which it says will create a two-tier workforce.
RMT general secretary Mick Lynch said: “Tube workers who help bring vast amounts of value to the London economy are not going to put with senior managers and commissioners raking it in, while they are given modest below inflation offers.
“The refusal of Transport for London (TfL) not to restore staff travel facilities and create a two-tier workforce is also unacceptable.
“Our members will now decide whether to set a mandate for strike action over pay and we urge TfL to improve their offer to avert disruption to Londoners.”
The ballot closes on December 19.
The union had earlier this month extended its strike mandate on the Tube for six months, raising the prospect of more disruption for commuters in the long-running industrial dispute.
Members of the union separately walked out on the Docklands Light Railway for 48 hours earlier this month over pay.
The union has repeatedly brought the London Underground to a halt throughout this year with industrial action.
It had planned to take strike action last month, but this was suspended after “significant progress” over job changes and changes to rosters.
However, wider negotiations are still continuing over pensions and working agreements.
TfL has said it believes any changes would create a “fairer, more efficient” London Underground and “give an even better and more reliable service” to passengers.
It comes after the union reached a possible breakthrough with mainline rail operators, which could possibly avoid strike-related disruption at Christmas like last year.
