Australian Navy signs agreement for $50b fleet of subs

After several years of negotiations, officials have signed an agreement for the construction of the Australian Navy's fleet of new submarines.

The federal government today announced the signing of the Attack class submarine Strategic Partnering Agreement with French shipbuilder Naval Group.

Defence and Naval Group officials have been locked in negotiations for several years to produce the 12 submarines.

In December there were reports the $50 billion project could arrive late and cost millions more than expected.

However, a joint statement from Prime Minister Scott Morrison and Defence Minister Christopher Pyne said work would continue on the first attack class submarine, to be named HMAS Attack, to deliver it within budget in the early 2030s.

The formal signing of the agreement is a "defining moment for the country," the statement said.

"The submarines will help protect Australia's security and prosperity for decades to come and also deepen the defence relationship between Australia and France," it continued.

Construction on the "regionally superior" submarines has already begun and work will continue under the agreement, which represents the contractual basis for the program, it said.

The submarines are a major pillar of the government's $90 billion National Shipbuilding Plan, under which 54 naval vessels will be built in Australia.

The development of the submarine construction yard at Osborne in South Australia is continuing as part of other activities required to deliver the program.