Malta Freeport management has been prohibited from negotiating with Union Haddiema Maghqudin until a court case over workers' union representation has been settled.
The Civil Court decision was based on a request by the General Workers' Union, which insists that it still holds the right to represent Freeport workers.
UHM claimed victory in an election held among Freeport workers earlier this week, saying that it would henceforth represent workers there.
But the GWU is insisting that the rules make it clear that a union must obtain 50 per cent plus one of the entire Freeport workforce if it is to win the right to represent workers. UHM won the election but not the majority of the total workforce.
The case will continue on 16 May.