“I get that nuclear submarines are very capable. As a former submariner and having spent time at sea on the nuclear USS Santa Fe, I get it more than any other member of the federal parliament,” he said.

“But I also understand the capabilities of modern hydrogen fuel-cell submarines.”

He recommends a $20 billion spend on 20 highly capable submarines, rather than an estimated $171 billion on eight nuclear-powered vessels.

Call to dump nuclear, go hydrogen for subs | 7NEWS