Workers at the port of Felixstowe are to strike for eight days later this month in a dispute over pay.
Members of Unite will walk out on August 21 after talks at the conciliation service Acas failed to resolve the row.
Unite said more than 1,900 workers at Felixstowe, the country’s biggest container port, will be taking industrial action.
The strike was called after Unite said the Felixstowe Dock and Railway Company failed to improve on its offer of a 7% pay increase, describing it as “significantly below” inflation.
Unite general secretary Sharon Graham said:“Both Felixstowe docks and its parent company CK Hutchison Holding Ltd are both massively profitable and incredibly wealthy. They are fully able to pay the workforce a fair day’s pay.
“The company has prioritised delivering multi-million pound dividends rather than paying its workers a decent wage.
“Unite is entirely focused on enhancing its members’ jobs, pay and conditions and it will be giving the workers at Felixstowe its complete support until this dispute is resolved and a decent pay increase is secured.”
The workers undertake manual roles at the docks including crane drivers, machine operators and stevedores.
Unite national officer Bobby Morton said: “Strike action will cause huge disruption and will generate massive shockwaves throughout the UK’s supply chain, but this dispute is entirely of the company’s own making.
“It has had every opportunity make our members a fair offer but has chosen not to do so.
“Felixstowe needs to stop prevaricating and make a pay offer which meets our members’ expectations.”
Further talks are scheduled to take place at Acas next Monday.