Managers at Milford Haven port have successfully secured a High Court injunction against a 48-hour strike by about 50 pilots and launch crew.
The strike was due to take place today (Thursday 18 February) and tomorrow in a protest over changes to the pension scheme.
The High Court judge ruled that notices of industrial action issued by the Unite union did not fully comply with the 1992 Trade Union Act, giving employers seven days notice of strike action, the Guardian reported.
Justice Sweeney said that the "balance of convenience" favoured the port authority.
Unite has now issued Milford Haven port with seven days notice that the workers will stage a 12-hour strike on 23 February. They will also start an overtime ban and work-to-rule starting on the same day.
The port wants to move from a non-contributory pension scheme to a contributory one; change the scheme from a final salary to a career average one; and also raise the retirement age to 65 from 60.
The port authority has argued it must alter its pension provision because of a huge deficit, which is growing and unsustainable.
Brendan Gold, Unite's national secretary for docks and waterways, said: "The fundamental issue here is the High Court intervening yet again, as they did in the BA cabin crew dispute, to undermine our members' democratic decision to take industrial action.
"It is hugely frustrating going through the correct legal procedures to call this action then to have the courts intervene to block it. The courts are now actively intervening in industrial relations' disputes."