Royal Mail workers will launch a fresh, 48-hour strike on Thursday in a dispute over pay, which threatens disruption to deliveries.
The Communication Workers Union (CWU) said 115,000 of its members will walk out in protest against an “imposed” 2% pay rise.
Picket lines will be mounted outside delivery and sorting offices, following strikes last week, and there is a prospect of further industrial action if the deadlock is not broken.
The union said its members face a “dramatic” reduction in living standards because of the soaring rate of inflation.
CWU general secretary Dave Ward said: “There can be no doubt that postal workers are completely united in their determination to secure the dignified, proper pay rise they deserve.
“We can’t keep on living in a country where bosses rake in billions in profit while their employees are forced to use food banks.
“When Royal Mail bosses are raking in £758 million in profit and shareholders pocketing in excess of £400 million, our members won’t accept pleads of poverty from the company.
“Postal workers won’t meekly accept their living standards being hammered by greedy business leaders who are completely out of touch with modern Britain.
“They are sick of corporate failure getting rewarded again and again.
“Royal Mail’s leadership have lost the dressing room – and unless they make efforts to get real on discussing a pay rise that postal workers deserve, serious disruption will continue.”
CWU deputy general secretary Terry Pullinger said: “Our members worked miracles during the pandemic and know full well what they are worth.
“They are fighting for a no strings, real-terms pay rise – something they are fully entitled to.
“Our members deserve a pay rise that rewards their fantastic achievements in keeping the country connected during the pandemic, but also helps them keep up during this current economic crisis.
“We won’t be backing down until we get just that.”
A Royal Mail spokesperson said: “We apologise for the impact the CWU’s industrial action is having on our customers. We are doing all we can to minimise any delays and keep people, businesses and the country connected.
— The CWU (@CWUnews) September 5, 2022
“This week, after many invitations, the CWU finally agreed to Royal Mail’s request to meet at the most senior level to decide on a way forward on the industrial dispute.
“Rather than engage on the need for change, the CWU restated their demands to retain the current outdated working practices, which includes working fewer hours for more pay.
“We are greatly concerned that the CWU are simply not interested in discussing the change needed to modernise this business and protect well-paid, permanent jobs long-term.
“The CWU declined our request to call off their strike action this Thursday and Friday. The CWU’s approach is setting us on a perilous path.
“Royal Mail is losing £1 million a day and strike action has weakened our financial position. Further strikes will make it weaker still. Without meaningful engagement on the change that is needed from the CWU, the position of the company will worsen and put jobs at risk.
“We remain ready to talk with the CWU to try and avert damaging industrial action and prevent further inconvenience for customers, but any talks must be about both change and pay. Change is the route to higher pay.”
The CWU has described the strikes as the biggest of the summer, which has also seen industrial action by rail workers, Openreach engineers, BT call centre staff, refuse collectors and barristers.