London Underground workers have voted overwhelmingly in favour of extending their mandate to continue taking strike action in a long-running dispute over jobs, pensions and conditions.
Members of the Rail, Maritime and Transport union (RMT) voted by 96% to continue taking action for the next six months.
Unions have to re-ballot their members every six months for industrial action to continue.
The turnout was 56.5%.
RMT general secretary Mick Lynch said: “I congratulate every single one of our London Underground members for giving us continued industrial leverage at the negotiating table.
“Transport for London cannot continue to simply wish this dispute away and the Government, which has drastically cut the funding to London transport budgets, shares a great deal of responsibility for this continuing impasse.
“London Underground workers want a negotiated settlement and are quite prepared to take more strike action over the next six months to make that a reality.”
The Government is pressing ahead with legislation aimed at providing minimum levels of service during strikes.
There was a protest outside Parliament on Monday evening when the Bill was voted through by MPs.
It will be debated in the Lords again before becoming law in the next few weeks.