Prime Minister Malcolm Turnbull has announced French contractors will build the Royal Australian Navy’s new submarines.

Mr Turnbull made the announcement in South Australia this morning, along with the Ministers for Defence and Industry, and the Chief of the Navy.

He said the submarine project would generate 2,800 jobs.

France, Japan and Germany were considered the frontrunners to win the $50 billion contract, which will see the construction of 12 new submarines, two offshore patrol ships and the launching of a future frigate program.

Defence Minister Marise Payne said work would start in 2018, but work in Adelaide would start in 2020.

French Industrial building company DCNS will help design the subs, which will be built in Osborne, South Australia.

“This is securing the future of Australia’s Navy, over decades to come,” Mr Turnbull said.

Mr Turnbull said the project would see Australian workers build Australian submarines with local steel.

Ms Payne said the selection process had been rigorous and had taken 15 months from February, 2015.

More than 60 meetings were held during the selection process to ensure Australia’s unique building requirements could be met.

“Submarines are a strategic capability, providing Australia with advantages in the challenging maritime environment in our region,” Ms Payne said.

“Our decision to expand our fleet to 12 regionally superior submarines is a decision driven by national security. DCNS’ proposal best met Australia’s unique requirements.”

Industry Minister Christopher Pyne said today’s announcement secured jobs for Australians.

“It secures Osborne as the centre industry for naval ship building into the future,” he said.

Chief of Navy Tim Barrett said the Navy’s future was now secure because of the funding project.

Premier Colin Barnett said the WA steel industry would also benefit from the project, with pacific patrol vessels and the offshore patrol vessels set to be built at the Australian Marine Complex in Henderson.