Maintenance and operations workers at London Cable Car have vowed to strike on Saturday in a row over pay, a union has said.
The Rail, Maritime and Transport union (RMT) said its members could take further action for months if a dispute over pay is not resolved.
The river crossing connects North Greenwich to the Royal Docks in east London.
Union officials announcing the industrial action said members at Doppelmayr Cable Car (DCC) have not received a decent pay offer.
The cable car workers will take strike action every Saturday until February next year if a deal is not reached, the union vowed.
RMT general secretary Mick Lynch said: "The behaviour from Doppelmayr management has been appalling. Instead of trying to work with the union to find a resolution, they have sought to ratchet up this dispute believing they can punish RMT members without the union responding.
"Our members work long hours to maintain this unique form of transport in London and yet are being treated with disdain and zero respect.
"That cannot continue, which is why they will take strike action every Saturday for six months, unless a negotiated settlement can be found."
Since the 2012 London Olympics, the cable cars have adorned the sky between North Greenwich and the Royal Docks.
The £60 million gondola line, the only one of its kind in the capital, crosses the River Thames over a length of almost 1,100 metres and can carry to 2,500 passengers per hour.
IFS began sponsoring the cable car in October 2022 under a two-year deal with TfL.
An IFS spokesperson said: “IFS is the very proud sponsor of London's iconic IFS Cloud Cable Car. We wish both parties the best for a swift and mutually satisfactory outcome.”
