Opposition Leader Bill Shorten has called on Malcolm Turnbull to "do something about his backbench", saying Tony Abbott is acting like both the prime minister and foreign minister.

The former prime minister delivered a speech in Japan overnight, in which he argued for more freedom of navigation military exercises in the contested South China Sea, and said China and Australia did not share the same values.

Mr Shorten said Mr Abbott giving speeches on foreign policy was a "recipe for chaos".

"When you see the former prime minister taking a very different priority to Mr Turnbull on foreign policy — this is a divided Government, and a divided Government is not good for Australia, is not good for Australian jobs, is not good for Australia's position in the world," he said.

"Malcolm Turnbull needs to do something about his backbench. I've got some respect for the fact that Tony Abbot was prime minister, so he should be given a little bit more rope than some of the more right-wing characters.

"What I don't understand is why Malcolm Turnbull has got senior members of his own Government out there giving their own speeches on foreign policy."

In his Tokyo speech, Mr Abbott said China's activities in the disputed South China Sea were threatening the region's stability.

"[Australia] should be prepared to exercise our rights to freedom of navigation wherever international law permits, because this is not something that the United States should have to police on its own," he said.

"Countries which turn reefs into artificial islands at massive environmental cost, fortify disputed territory and try to restrict freedom of navigation are putting at risk the stability and security on which depends the prosperity of our region and the wider world."

Mr Abbott also said the communist nation did not share the same "values" as Australia.

He said Japan and Australia had a relationship "not based simply on shared interests, but also on shared values", whereas China and Australia had an "interests partnership rather than a values one".