Royal Mail workers have overwhelmingly voted to renew their strike action mandate - setting the stage for the possibility of six more months of disruption.
The Communication Workers Union (CWU) announced that members had voted by 95.9% on a 77.3% turnout to take further strike action.
General Secretary Dave Ward said: “After two national ballots, 18 days of action, constant management intimidation and scores of unjust disciplinary cases against their colleagues, postal workers have shown their dignity and determination once again.
“This vote is a historic testament to CWU members across the country who have stood firm against the most severe attacks faced by any set of workers since the miners."
He added: “These people will never be bullied, intimidated or harassed into submission, and this result is a concrete demonstration of that spirit.
Hospitals run out of oxygen and mortuaries full amid NHS chaos“I urge responsible voices in Royal Mail’s leadership to take stock of what has happened today.”
A massive 96.7% of posties voted first for strike action in June 2022 on a turnout of 77% in the dispute over pay.
It comes as the country continues to face mass walkouts in other sectors, including the NHS, civil service, rail, universities, and schools.
Ministers have so far resisted negotiating over pay with public sector bodies, including the health service - despite the surging cost-of-living and sky-high inflation.
The Royal College of Nursing (RCN) has accused ministers of refusing to engage in talks and is threatening to escalate industrial action in the coming weeks.
On Wednesday education union bosses also made clear that further strikes by teachers would go ahead later this month after "disappointing" talks with ministers.
Kevin Courtney, the joint general secretary of the National Education Union (NEU), said a meeting with the Education Secretary Gillian Keegan had a "better tone" than previous talks.
But he stressed there was "no movement" from the Government.
"There is nothing in it that could persuade us not to go ahead with the action that we've got scheduled for the week after half-term."