Royal Mail has won a High Court injunction to block potential strikes by postal workers.
The company brought legal action against the Communication Workers Union (CWU) after members voted to back walkouts by 97% on a turnout of 76%.
At the outset of a ruling in London on Wednesday, Mr Justice Swift said he had decided that there should be an order for an injunction.
During a hearing on Tuesday, Royal Mail claimed the union orchestrated a “de facto workplace ballot”, contrary to rules on industrial action, to maximise the turnout and the “yes” vote.
CWU lawyers argued there was no evidence of interference with the ballot and that “legitimate partisan campaigning” by the union in favour of a “yes” vote did not violate the rules.
The CWU balloted members over strike action amid a dispute between workers and management over job security and employment terms.
The union previously said the result of the ballot, which was open between September 24 and October 15, represented the largest “yes vote” for national industrial action since the passing of the Trade Union Act 2016.
The CWU sent out a brief tweet immediately after the ruling, which said: “Genuinely this is an utter outrage. 110,000 workers vs the establishment.”
CWU general secretary Dave Ward said the union will do everything in its power to oppose the decision, including appealing against the judgment after guidance from its lawyers, re-balloting and launching a “huge leverage campaign” with major shareholders against the company’s actions.
He said: “CWU members will be and are extremely angry and bitterly disappointed that one judge has granted Royal Mail an injunction to invalidate our ballot for strike action.
“We balloted over 110,000 members and they voted by over 97% in favour of strike action in a massive 76% turnout.
“Not one single person out of 110,000 who were balloted complained to Royal Mail that their right to vote was interfered with. Not one single person out of 110,000 who were balloted complained to the independent scrutineers that their right to vote was interfered with.
“The Electoral Reform Society who conducted the ballot confirmed it was run in full accordance of the law, and after over seven weeks since the ballot commenced, not one single person has complained to the certification officer who is appointed by the Government to regulate trade unions.
“Yet despite all of this – with no evidence supporting their claim from any employee – Royal Mail can come to this court in what is a cowardly and vicious attack on its own workforce.
“We have run a fantastic modern-day campaign that combines face-to-face meetings with use of social media to engage willing members to maximise the Yes vote and turnout.
“Members participated and cast their vote of their own free will. To suggest otherwise is to insult the intelligence and the integrity of thousands and thousands of good, hard-working people.
“We will be considering the judge’s detailed reasons for this but we want to make it clear that the only thing this union, its representatives and its members have done is to run a fantastic modern-day campaign to engage and encourage workers to defend their jobs.
“This injunction is not only a massive injustice to our members, it’s also an injustice to every worker in the country.
“We all need to wake up and recognise that this Tory Government has deliberately stacked the rules against workers in favour of the constituency they were born to serve – which is big business and the establishment.”