Defence secretary Greg Moriarty has confirmed his department is looking at alternatives to French-designed submarines in case the troubled contract is sunk.
Mr Moriarty would not reveal what fallback options were being explored but described the process as "prudent contingency planning".
"It's prudent that defence is looking at alternatives if we are unable to proceed," he told a Senate hearing on Wednesday.
"We are very committed to delivering the Attack (class submarines) but it's appropriate that we would be looking at alternatives if we were unable to proceed."
There are serious tensions between Australia and the French shipbuilding company, with the $90 billion submarine contract plagued by multiple cost and timetable blowouts.
Mr Moriarty was pressed on whether he had provided more regular advice about the submarine contract to ministers over the past year.
"I have certainly thought more about this issue over the last 12 months because it became clear to me that we were having challenges with the Attack class program over the last 15, 12 months," he said.
"So of course, you do reasonably prudent thinking about what one of those options might be, or what you might be able to do if you are unable to proceed.
"But the government is absolutely committed to trying to work through with Naval Group and build a regionally superior submarine in Adelaide."
