The ability of China to cut fuel supplies to Australia by blockading shipping lanes was a key example of why a fleet of nuclear-powered submarines was required, Defence Minister Richard Marles has argued.

In a speech to parliament to hit back at criticisms of the AUKUS pact by Paul Keating and others in the labour movement, Mr Marles also portrayed as out-of-touch a suggestion by the former prime minister that Australia should eschew nuclear subs and instead build another 40 to 50 diesel-powered Collins Class submarines to defend itself.