Submarine workers walk off docks over pay dispute

The protected action at the Osborne Naval Shipyard will continue until next Monday, when union workers will attend a meeting to discuss further action.

The union said ASC workers in Western Australia are paid an average 17.5 per cent more than ASC workers in South Australia.

It says the disparity has been ignored during enterprise bargaining negotiations and the latest offer from ASC was 7 per cent short of parity, which members of the AMWU and two other unions had rejected.

The unions say they have offered offsets, productivity improvements and cost-saving measures, but they have been ignored by ASC.

Workers were frustrated, AMWU SA assistant state secretary Stuart Gordon said.

"ASC can afford to pay its workers. It just doesn't want to," he said.

"The argument it presents about economic and environmental factors is redundant given how the cost of living is affecting South Australians and the essential skills the SA team provides to ASC."

The federal government has signed a $2.2 billion, four-year deal with ASC to ensure the Collins submarines are operational into the 2030s and beyond, until their replacement by second-hand nuclear-powered Virginia Class submarines purchased from the US under the AUKUS partnership.

The AMWU said the SA workforce would be "critical to the future AUKUS fleet", with many of the workers currently seconded to the US for training on the new technology.

The navy has only half its submarines at its disposal with HMAS Sheehan, HMAS Rankin and HMAS Farncomb out of action for the rest of the year.

Mr Gordon said ASC chief executive Stuart Whiley was "incompetent".

"He has told the government that there will not be any delays in the boats' schedule, but those boats are stranded due to the stoppages. Clearly this will continue until workers are paid fairly," he said.

ASC has been contacted for comment.