More than 1000 shipbuilders plan to rally outside the Adelaide office of federal Industry Minister Christopher Pyne to urge the government to build submarines in South Australia.
The workers were to march to Mr Pyne's office on Friday.
"The coalition promised to build 12 submarines at ASC in Adelaide," Australian Manufacturing Workers' Union assistant national secretary Glenn Thompson said.
"Voters and workers expect the government to honour that election promise in order to boost the Australian economy and protect our national security."
The rally comes a week after the AMWU unveiled a series of "Subs=jobs, build them all here" billboards in Adelaide.
The federal government is undertaking a competitive evaluation process for Australia's next fleet of submarines.
Under consideration are a local build, an overseas build, and a hybrid build that would have some work done in Australia and some overseas.