Royal Mail has won a High Court injunction preventing next week's 48-hour strike by postal workers.
Earlier in October, members of the Communication Workers Union (CWU) voted massively in favour of industrial action, with 83% of those who voted backing the idea in a dispute over pensions, pay and jobs.
The strike had been scheduled to begin at noon on October 19.
Royal Mail says the CWU is in breach of its contractual obligation not to call for strike action until the external mediation process, which began on October 5, is exhausted.
It claims that an injunction is appropriate to prevent the deliberate inconveniencing of hundreds of thousands of people across the UK, as well as commercial loss to the company.
The CWU maintains it has been attempting to find a solution to the dispute for 18 months.
Granting the order, Mr Justice Supperstone said he considered "the strike call to be unlawful and the defendant is obliged to withdraw its strike call until the external mediation process has been exhausted".
The CWU has accused Royal Mail of carrying out a "relentless" programme of cost-cutting to maximise short-term profits and shareholder returns.
The union said the company had closed its defined benefit, or final salary, pension scheme, offering new entrants an "inferior" scheme which the CWU claim will leave them in "pensioner poverty".
The industrial action would have been the first strike at Royal Mail since the postal group was privatised in 2015.