South Australia fears the defence white paper will open the door for an erosion of its shipbuilding work.
Thursday's white paper will outline major acquisitions including nine new frigates, a number of offshore patrol vessels and a new fleet of submarines.
SA Defence Industries Minister Martin Hamilton-Smith is concerned the paper won't specify an Adelaide build for the patrol vessels, which he says is vital for local industry.
There are fears the vessels will instead be built in Western Australia.
Mr Hamilton-Smith believes this would decimate SA's shipbuilding workforce, bringing on the "valley of death" even if the future submarines are built locally.
The "valley" refers to the years between the end of current projects and the start of new projects, when shipbuilders have to lay off many of their skilled workers.
"Whoever gets that will be well-placed to become the future for naval shipbuilding going forward, regardless of what promises are made," he told reporters on Wednesday.
"We won't be launching the first frigate until around 2022 ... and the first submarine sometime in the mid-2020s. There could be four federal elections between now and then.
"Unless there is unreserved and unequivocal commitment to build those patrol vessels in SA in this white paper, South Australian industry and workers have every reason to be worried."
Former prime minister Tony Abbott last year announced that a $39 billion program to build new frigates and offshore patrol ships would be centred in Adelaide.
But newly-appointed Defence Minister Marise Payne has taken a different tone, saying the competitive evaluation process for the patrol vessels contract didn't require them to be built in Adelaide.
Australian Made Defence spokesman Chris Burns said building the patrol vessels and future frigates at the same site in Adelaide was the only way to avoid cost blowouts and delays.
"If we have to rebuild the workforce and the skills from scratch, it is Australian taxpayers who will wear the costs," he said.
