Royal Mail workers will walk out in fresh strike action amid a long-running dispute over pay and conditions.
Members of the Communication Workers Union (CWU) announced that they will walk out on February 16, threatening more disruption to mail deliveries.
The strike was announced despite talks last month at the conciliation service Acas aimed at breaking the deadlocked row.
A series of strikes were held last year, including in the weeks running up to Christmas and some of the busiest postal days such as Black Friday and Cyber Monday.
CWU general secretary Dave Ward said: “This action is down to the conduct of Royal Mail management, who have displayed a complete lack of integrity.
“Our members will not just sit back and watch as their working lives are destroyed by a company leadership hell-bent on ripping up historic arrangements that protect their rights and give them a voice through their union.
“It is postal workers who keep this company going and this country connected – it’s time management recognise this, drop the nasty games and begin taking negotiations seriously, so that this dispute can be ended for good.”
A Royal Mail spokesperson said: “We entered facilitated talks through Acas in good faith, believing that the CWU were serious in their claim that they wanted a resolution.
“In announcing further damaging strike action, the CWU have shown they are not interested in resolving this dispute and continue to focus on damaging our business further.
“The CWU’s misguided belief that further industrial action will remove the need for change and force an improved offer is misleading its members and risking their long-term job security.
“Their 18 days of industrial action have resulted in £200m losses in the year to date, cost our people around £1,800 in lost pay and inconvenienced our customers.
“We need to agree on changes to make our business more competitive. That is the only way to secure well-paid, long-term job security for our people.
“In a materially loss-making company, with every additional day of strike action, we are facing the difficult choice of whether we spend our money on pay and protecting jobs or on the cost of strikes.
“We remain committed to talks and urge the CWU to withdraw these strikes for the good of our customers and our people.”