The manufacturing workers union wants the government to bring forward major naval shipbuilding projects or risk 3000 jobs.
Australian Manufacturing Workers' Union assistant national secretary Glenn Thompson says the clock is ticking and they can't wait for the new Defence White Paper in a year.
"We need an immediate decision. The valley of death is upon us. Some 3000 jobs are at risk," he told reporters.
Mr Thompson led a delegation of workers from shipyards in Newcastle, Melbourne and Adelaide to Canberra to press the government for action on shipbuilding.
He said Labor's 2013 Defence White Paper proposed construction of some 50 new vessels over the next 30 years.
But work on two current projects for three new air warfare destroyers and two large landing helicopter dock ships will end long before new projects start.
That period between the end of old projects and the start of new work, when shipyards have no choice but to lay off skilled workers, has been termed the valley of death.
Mr Thompson said the government should bring forward projects to build replacement patrol boats and two new supply ships. It should also speed up plans for replacing the navy's eight Anzac frigates.
"This is a once in a lifetime opportunity for this government to step up to the plate to deliver some certainty," he said.
