Turnbull 'deeply disappointing': Treasurer

Treasurer Josh Frydenberg - who is being challenged for his Kooyong seat by independent Monique Ryan - labelled his former leader's comments "deeply disappointing". 

Mr Turnbull gave a speech at the Washington Harvard Club on Friday morning Australian time on Australia's system of democracy and "small l" liberal independent candidates.

Mr Turnbull said the Liberal Party was once a broad church of liberal and conservative traditions, but since his "deposition in 2018" moderate voices had become increasingly marginalised.

"Even if the members of a political party cannot escape from the thrall of the dominant faction, their traditional supporters in the electorate can do so by voting for an independent who has a real chance of success," he said. 

Prime Minister Scott Morrison and Mr Frydenberg have repeatedly said independents would cause parliamentary chaos and weaken Australia's national and economic security.

But Mr Turnbull argues instability and chaos often comes from within the party.

"Political instability invariably comes from internal ructions within the major, governing parties not from independents on the cross benches," he said.

"Many parliaments, including in Australia, have operated with stability and good effect with major parties requiring the support of independents or minor parties to pass legislation."

Mr Frydenberg claimed Ms Ryan was masquerading as an independent and a vote for her was essentially a vote for Labor.

"It's deeply disappointing to see those comments ... in the case of Monique Ryan, she's described (Turnbull) as a national disgrace," he told reporters in Melbourne on Friday.

"So I don't know how Malcolm Turnbull could endorse somebody who called him a national disgrace."

Mr Turnbull denied he was telling Australian voters what to do on May 21, saying the speech was for an American audience. 

"(The speech) is really pointing out how features of our ... electoral system make Australian democracy more resilient and offer people more choice and I think that's a very good thing," he told reporters in Washington. 

"I'm not telling anybody who to vote for, but I think it's very important that we have a democracy that is resilient.

"Australian democracy ... does give the opportunity for people to support alternatives and that's what the teal independents are." 

Mr Turnbull declined to comment on who he will be voting for on May 21 in his old federal seat of Wentworth in Sydney, saying it's a secret ballot.

The incumbent, Dave Sharma, is fighting for his political life against high profile teal independent Allegra Spender, whose father is a former federal Liberal MP and minister.

But Mr Joyce - who served as Mr Turnbull's deputy prime minister between 2016 and 2018 - said the former prime minister only wanted to create chaos. 

"Malcolm Turnbull is the ultimate entitled person," he told Sky News on Friday. 

"It's not about Mr Turnbull just tossing out his former allegiance to the party that made him the prime minister of Australia ... he understands politics and he's inherently going to inspire a process that makes our nation weaker."