No off-the-shelf submarines for Australia, Defence Minister Johnston says

Australia won't be buying submarines off-the-shelf because there aren't any in the world capable of meeting the nation's future strategic needs.

Australia's future submarine needs superior characteristics in stealth, range and endurance, sensor performance and hitting power, Defence Minister David Johnston told a conference in Fremantle yesterday.

"The next submarine will have longer range and endurance than any diesel-electric submarine currently available off-the-shelf," he said.

That's likely to bolster the hopes of the South Australian government, which has been urging Canberra to ensure the new submarines are built by the ASC in Adelaide.

Senator Johnston said a design phase was needed as quickly as possible to avoid a capability and national security gap.

The SA Economic Development Board recently commissioned the National Institute of Economic and Industry Research to assess the impact of buying the subs overseas.

It found it would cost the federal government about $21 billion to build the subs either in Australia or overseas.

The national economy would take an extra $20 billion hit over 40 years if the subs were built overseas instead of locally, while about 4000 fewer jobs would be created, the report said last month.