On the same day that the management side issued this statement, the Catering Workers Union (CAF) – part of the Federation of Oil Workers Trade Unions (OFS) – withdrew from the talks. The employers then broke off negotiations over all three agreements and announced a lock-out. The CAF called a strike on 6 April. In response, the employers instituted a lock-out of all workers covered by the three agreements. The OFS stepped up the strike on 19 April by calling out members of the Union of Operator Employees (OAF) on the UK side of Frigg and shut down gas deliveries to the UK.
Both sides were called in by Norway’s chief state mediator three days later for mediation. This effort broke down, and everyone was summoned to Arne Rettedal, then minister for local government and labour. He made it clear that they had one night to negotiate, and fixed a new meeting for the next day. Since the overnight talks also proved fruitless, the minister informed unions and management on 26 April that the matter would go to compulsory arbitration. This meant the unions had to resume work. Gas deliveries to the UK had then been halted for six days.
One consequence of this conflict was that the Frigg workers undertook not to down tools on the UK side during future labour disputes. Ensuring that a stoppage of this kind did not recur was important for Elf. The company took the initiative on talks between those involved, and a protocol was established. Another nation could not be hit or harmed by disagreements on the NCS. The guarantee given by the workers was incorporated in the agreement on pay and conditions.