Thousands of Royal Mail workers will stage a rally on Friday to mark another strike in the increasingly bitter dispute over jobs, pay and conditions.
Members of the Communication Workers Union (CWU) will gather outside Parliament in central London, with little sign the long running row will be resolved soon.
The union said at least 15,000 will attend the rally, describing it as the biggest postal workers’ demonstration in living memory.
CWU General Secretary Dave Ward will also join one of the many picket lines which will be mounted outside Royal Mail offices across the country.
A Royal Mail spokesperson said: “We spent three more days at Acas this week to discuss what needs to happen for the strikes to be lifted.
“In the end, all we received was another request for more pay, without the changes needed to fund the pay offer.
“While the CWU refuses to accept the need for change, it’s our customers and our people who suffer. Strike action has already cost our people £1,200 each.
“The money allocated to the pay deal risks being eaten away by the costs of further strike action.
“The CWU is striking at our busiest time, deliberately holding Christmas to ransom for our customers, businesses and families across the country.
“We are doing everything we can to deliver Christmas for our customers and settle this dispute. During the last strike days, we delivered more than 700,000 parcels, and more than 11,000 delivery and processing staff returned to work.
“We recovered our service quickly, but the task becomes more challenging as Christmas nears.
“We remain willing to talk at any time about our best and final offer and urge the CWU to call off their damaging strike action.”