However,Mr Moriarty said the government was “absolutely committed to trying to work through with Naval Group and build a regionally superior submarine in Adelaide”.

A spokesman for Naval Group said the company was “fully committed to continuing to achieve important program milestones”.

“Significant progress has already been made on submarine design,workforce growth and Australian industry involvement,” the spokesman said.

Prime Minister Scott Morrison is expected to discuss the submarine project with French President Emmanuel Macron when they meet in Paris later this month.

Opposition defence spokesman Brendan O’Connor called on Mr Morrison to explain what changes could be made to thelargest Defence contract in Australia’s history.

“There has been no certainty about the future submarine for some time,yet it is only today we are hearing confirmation that the government is looking at other options for our submarine capability,” he said.

It has been reported Australian officials are now considering German options including submarines from TKMS and Saab.

Mr Moriarty would not comment on specific options but said,“it’s fair to say we’re looking at capability pathways,” when Labor senator Penny Wong asked whether Defence was engaging with other suppliers.

“I’m not going to go into those pathways but the Chief of Navy said that yesterday we’re not looking at the TKMS,” he said.

Commodore Tim Brown,who was previously the director-general of submarine capability and is now in a role looking at overall force structure requirements,repeatedly told the senators he could not discuss whether he was involved in considering alternatives because everything he did in that previous job was classified.

Independent senator Rex Patrick eventually lost his temper at this evasion,telling Commodore Brown everything he did was paid for by taxpayers.

“We have an oversight role and we are entitled to ask questions and we expect answers,” the senator said.