Hundreds of workers maintaining the navy's Collins class submarines could be relocated from Adelaide to Perth within three years, angering key crossbench South Australian senators who fear the loss of local jobs.

With criticism already strong that the defence industry build-up is being used for electoral pork barrelling, the taxpayer-owned shipbuilder ASC revealed it had been commissioned by the government to come up with options to relocate deep maintenance of the submarine fleet to their home port in Western Australia.