The RMT union said 162 staff from operator Serco Docklands voted to strike, with 36 voting against action in a dispute over pensions, working hours and redundancies.
David Stretch, managing director of Serco Docklands, said he was disappointed but hoped to defuse the protest: “Our aim is to resolve the current issues before any action is taken which disrupts our passengers.”
RMT general secretary Bob Crow said Serco has shown “total disregard for the idea of proper negotiation and consultation”. The union has not set a date for the walkout.
The news came a day after Southeastern workers at Victoria and Charing Cross stations voted to strike against station job cuts.