Former prime minister Kevin Rudd has reignited a bitter feud with Prime Minister Malcolm Turnbull, slamming his handling of what Mr Rudd calls the most important question of our times: the rise of China.

Mr Rudd has delivered a withering critique of Australia's policy toward its biggest trading partner, accusing Mr Turnbull's China strategy of being "absolutely all over the place".

He said the Federal Government is "incoherent and inconsistent" at a time when a powerful China is threatening to remake the global order and "we just don't know what the future rules will be".

Mr Rudd's criticism also comes with a warning: China is "contemptuous of weakness" and its growing strength, if mishandled, could escalate into war.

In an interview with ABC News program Matter of Fact, Mr Rudd savaged Mr Turnbull for going wherever "the political winds blow" and following Washington at a time when the US-China relationship is "in a deeply fragile state".

Mr Rudd will expand on his criticism in a major address he will deliver this week to Melbourne's La Trobe University on Australia's relationship with China.

He cautioned, at a time when China's media is telling its people daily that democracy and western traditions are in retreat, that Mr Turnbull needs to show consistency to China and build a relationship founded on defending Australia's values.

"What I would say to Mr Turnbull, is he needs to have a coherent China strategy, a consistent China strategy — one anchored in who we are as a western country in Asia, one which is mindful of the depth and breadth of the interests of the continuity of our security relationship with the United States, but with the diplomatic sensibility through all of the above — rather than simply go whichever way the political winds either here or in Washington happen to blow on a particular day," Mr Rudd said.

Mr Rudd's attack on Mr Turnbull dates back years — he points to Mr Turnbull's criticism of the former Labor government's hard line against the "China threat" in the 2009 Defence White Paper.

At the time, then-opposition leader Mr Turnbull questioned the proposed boost to Australia's defence funding, saying it was based on the anticipation of a major conflict with China that was "something most people would regard as being very unlikely and not realistic".

Mr Rudd's attack on Mr Turnbull dates back years. ( AAP: Alan Porritt )

Turnbull 'has history of being soft on China'

Mr Rudd also raised fresh questions about Mr Turnbull's favourable attitude in the past to Chinese communications giant Huawei.

As prime minister, Mr Rudd banned Huawei from involvement in Australia's National Broadband Network on the grounds of national security.

Mr Turnbull, then communications minister in Tony Abbott's government, argued, but failed, to have the ban reviewed.

At the time, Labor said Mr Turnbull had been humiliated by his leader Mr Abbott.

Now, Mr Rudd said it is evidence Mr Turnbull has a history of being soft on China, and is guilty of sending confusing, contradictory signals to Beijing.

"Turnbull has been all over the place on the China-Australia relationship, highly critical of me in the past for decisions on things like Huawei, highly critical in the past in terms of the robust posture adopted by our government on the question of the Defence White Paper … Turnbull has … blown hard and soft … Australia's national interest demands consistency of a view," Mr Rudd said.

Rudd 'still bitter' over UN job snub

Mr Rudd's attack on Mr Turnbull threatens to reopen still-fresh wounds after the two clashed in 2016, when Mr Turnbull refused to nominate Mr Rudd as a candidate for the post of secretary-general of the United Nations.

Mr Turnbull said Mr Rudd lacked the temperament for the role.

Mr Rudd replied that Mr Turnbull "concocted" the reasons for not backing the UN bid and was a "brick wall" to Mr Rudd's ambitions.

Australian Strategic Policy Institute head Peter Jennings said Mr Rudd is still "bitter" over the snub.

Mr Jennings was a key adviser on the latest Australian defence policy, and does share some of Mr Rudd's broader concerns.

However, he said Mr Rudd is also to blame for successive Australian governments' failure to grapple with China.

"I don't think Australian governments have got China right … this is the number one challenge — a big challenge. and I don't think any Australian government gets full marks," Mr Jennings said.

Mr Jennings did give Mr Turnbull credit for toughening his approach since becoming Prime Minister.

Beijing described Turnbull as 'China basher-in-chief'

Mr Turnbull has had his own at-times rocky relationship with China.

Beijing lashed Mr Turnbull for his comments about Chinese influence in Australian politics.

Chinese state media accused Australia of racism and being a puppet of Washington and Mr Turnbull has been described as "China basher-in-chief".

Mr Turnbull hit back at China at the time, saying he would "stand up" for Australia and has since announced tougher foreign interference laws.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 1 minute 3 seconds 1 m 3 s Prime Minister Malcolm Turnbull says China expects people to stand up for themselves

The Turnbull Government has also incurred the wrath of Beijing for expressing concern over China's claims on the disputed South China Sea.

Mr Rudd condemned Mr Turnbull for veering from "accommodationist to confrontationist" and said inconsistency is worrying at a time when China's strength presents an alternative authoritarian model to the world.

"China, in my study of the tradition over the course of my life, has a deep view of the rest of the world, which is, it is always contemptuous of weakness and a respecter of strength," Mr Rudd said.

Mr Rudd would not say explicitly that China views Australia as weak — but his comments leave little doubt he believes Mr Turnbull needs to show more strength.