Liberal Democrat David Leyonhjelm brought a tumultuous sitting week in Canberra to a close on Thursday night by declaring the nation could only have "truly Aussie" submarines if they were made in Eastern Creek in western Sydney.

In a five minute speech poking fun at the current ship building debate, Senator Leyonhjelm suggested Penrith muffler shop owner "Ferret" could make submarine shaped vessels "for much less than a billion dollars" and was willing to cut costs further by constructing them out of aluminium.

He stated the subs should have furry dice made of Goulburn merino wool, noisy V8 engines as well as "bumper stickers, commemorating various B&S balls, and reminding foreign invaders to "eff off, we're full".

"To make it completely Aussie, I propose that the whole Eastern Creek Submarine Corporation be overseen by Dick Smith," Senator Leyonhjelm said.

"There are only two kinds of Australians: people who live in New South Wales, and people with a chip on their shoulder."

He joked he wanted a plebiscite to see if Ford or Holden should manufacture the engines and mocked fellow Senators, like Nick Xenophon and Jacqui Lambie, for calling for their states to benefit from some of the submarine building work.

"Let's face it, vocational options for people in some of the states they represent are limited to working for a senator, or picking up road kill," he said.

"Who among us doubts that if we put submarines into the wrong hands, Senator Lambie may try a sneak attack on Bondi Beach, or South Australia could become the Republic of Xenophonia?"

Senator Leyonhjelm, who has suggested the Government buy second hand nuclear submarines, believes the $50 billion Collins Class replacement program is unnecessarily expensive and more about domestic politics than the nation's defence.

"None of this is about good submarines," he said in a brief moment of seriousness.

"The most important reason to adopt my modest proposal is that western Sydney is home to around 1 million voters. And isn't that what all this is about?"

South Australian MPs who played a significant role in Tony Abbott's ousting as prime minister believe Malcolm Turnbull is more likely to build the replacement submarines onshore, mostly in Adelaide.

High profile South Australian Liberal Christopher Pyne is tipped to get the Defence portfolio in a ministerial reshuffle this Sunday.