Any decision on the location of maintenance work for the Australian Navy's six Collins class submarines will be made in the national interest, not based on state politics, a senior cabinet minister says.
Federal cabinet is expected to make a decision as early as this week on the maintenance work - known as "full cycle docking" - which involves around 700 shipyard jobs and is currently worth $400 million a year to South Australia.
Senior cabinet members who are based in Western Australia are arguing for the work to be shifted to the wholly government-owned company ASC's Henderson facility in their state.
However, South Australians want the work to stay there, as well as the anticipated $89 billion in construction work on Australia's new fleet of attack submarines starting in 2024.
SA-based trade minister Simon Birmingham said there were broader factors to be considered.
"Prime Minister Morrison has been emphatic in his position that he wants this determined purely in the national interest, purely on what is going to support our Navy and air capability needs most effectively and efficiently for the long term," Senator Birmingham told Adelaide ABC radio on Monday.
"He hasn't been interested in politicking from anybody on this topic."
Senator Birmingham, who is not a member of cabinet's national security committee, said his view was (that) as long as the land, facilities and skills are available to continue to deliver the work in SA then it ought to continue there.
"But that is the prime question that Defence is answering."
It has been speculated the work could be split between SA and WA, or that blue collar jobs could move to WA while white collar engineers remain in SA.
Experts have argued SA facilities and workers would be overstretched when work begins on building the new fleet.
Labor MP Josh Wilson, whose electorate takes in the WA submarine facility, said consolidating full-cycle docking in his home state in 2024 was in the national interest.
He said a multi-billion dollar "banquet table" - the defence shipbuilding program - had been set in Adelaide.
"The only question is whether Western Australia gets a half-decent meal out of this long-running work program," he said.
Mr Wilson said a shipbuilding hub on the Indian Ocean was in Australia's national interest.
"And it's not in the national interest to put all our infrastructure and workforce eggs in a single basket."