Royal Mail workers are to stage a 48-hour strike in a "watershed" dispute over pensions, pay and jobs.
Members of the Communication Workers Union will walk out at noon on October 19 after voting massively in favour of taking industrial action.
General secretary Dave Ward said: "This is a watershed dispute that will determine not only our members' pensions, jobs and pay but also the future of the service.
"Postal workers delivered a massive Yes vote for strike action and we are determined to take whatever steps are necessary to deliver an agreement that will protect and enhance our members' terms and conditions and improve the range of services on offer to customers.
"As well as this call to action, the CWU will now launch a major campaign to gain public and political support for postal workers.
"This is your service. We must work together to save it."