The Royal Mail is facing the threat of the first national strike since it was privatised after workers voted massively in favour of industrial action in a bitter dispute over pensions, pay and jobs.
Members of the Communication Workers Union (CWU) backed walkouts by 89% on a turnout of 73% of the 110,000 balloted.
It passed the threshold in the Government’s controversial Trade Union Act, under which ballots need a 50% turnout for industrial action to go ahead.
The CWU believes it is a “watershed” moment for unions as well as the Royal Mail, which it has accused of following a “relentless” programme of cost-cutting to maximise short-term profits and shareholder returns.
The union accused the company of “unilaterally” closing its defined benefit, or final salary, pension scheme, with new entrants going into an “inferior” scheme which will leave them in “pensioner poverty”.
The union is also in dispute over pay and issues such as delivery office closures.
The union’s deputy general Secretary Terry Pullinger said: “This ballot result is hugely significant and demonstrates a strength of feeling that can only be translated as a massive vote of no confidence in the managerial leadership of the Royal Mail Group and the direction that they advocate.
“Any sense of vocational spirit and working together with management has been lost in a climate of fear and insecurity.
“This massive failure in trust has created a breakdown in relationships and a toxic environment where working together to solve difficult problems has become almost impossible.
“The managerial leadership has failed and should resign or be sacked.
“This is a dispute about honour and we refuse to simply stand aside.”
General secretary Dave Ward said: “This is a fantastic result for our members and indeed the wider trade union movement.
“As the first union to test the Trade Union Act we have passed with flying colours.
“The CWU have tapped into a mood amongst workers in across the UK. Our members are prepared to stand up and fight to protect their terms and conditions and we will do everything within our means to defend them.”
The CWU Postal Executive will meet later this week to determine the next steps in this campaign and any potential strike dates.
Mr Pullinger said Royal Mail bosses should resign or be sacked for the direction they are taking the company in.
He told a news conference in Manchester, close to the centre where the Conservative Party is holding its annual conference, that the union was being “progressive”, suggesting new products and services, including becoming involved in care in the community projects.
“Unfortunately Royal Mail is looking in the rear view mirror, taking us backwards. All they are interested in is minimising costs and maximising profits for shareholders.
“If they are successful, we will be sitting here in a few years’ time asking whatever happened to our postal service.”
Mr Pullinger declined to be drawn on whether a strike could hit the Christmas post, saying that the Trade Union Act had changed the rules of engagement, so that unions had six months to resolve a dispute or it could have to hold a fresh ballot.
“This is an emphatic result. We are fighting to stop a great public service from being ruined.”
Mr Ward said negotiations started 18 months ago, and unless the Royal Mail changed its position, industrial action was “inevitable”.
He said: “Postal workers have completely rejected the direction the company is going in. The only way the company can resolve this is by investing in its workforce. We want to see the service improved and enhanced, which is what we were promised when Royal Mail was privatised.”