Mr Turnbull, whose father led the Liberals until he was ditched as prime minister in August and left parliament, has committed to fund independents to run against senior government MPs, including Tony Abbott, Barnaby Joyce and Energy Minister Angus Taylor, at the next federal election.

The 26-year-old fund manager, based in Singapore, has been a vocal opponent of the Liberal Party’s right wing ever since Scott Morrison replaced his father.

He was extremely active in the weeks before the by-election in Mr Turnbull’s old seat Wentworth, urging voters to send the Liberals a message.

He eventually got behind the candidacy of independent Kerryn Phelps, who defeated Dave Sharma to win the seat and rob Mr Morrison’s government of its majority in parliament.

Speaking to The Guardian, Mr Turnbull promised he would both donate his own money and help raise more to help “small-L liberal” candidates.

He specifically identified National Farmers Federation President Fiona Simson as someone he could support if she decided to run against the former Nationals leader, Mr Joyce, in the seat of New England.

Media commentator Jane Caro has toyed with the idea of running against Mr Abbott in Warringah.

Whoever he chooses, Mr Turnbull wants someone who supports action on climate change.

“This issue is, if you are going to win, you need someone with local credibility, who is practical and reasonable. Their only real barriers are cash and organisational support. Cash often solves organisational issues,” Mr Turnbull said.

“Independents can be very constructive and helpful members of parliament. They haven’t been brutalised by the major party machines.

“There is something happening here, but we have to make sure people are resourced.”

During his Q&A appearance on Thursday night, Malcolm Turnbull voiced his own support for “small-L liberals”, suggesting the party he so recently led was drifting too far to the right.

He pointed out that three formerly safe Liberal seats — Wentworth, Indi and Mayo — had fallen to small-L liberal independents in recent years.

“In order to be successful as a political movement, you have to win votes from the centre,” Mr Turnbull said.

“The voters are saying they are concerned that the Liberal Party is not speaking for small-L liberal values.

“What you’ve seen increasingly from the right, even if they’re not in the majority, they’ll say, ‘If you don’t give us what we want, we’ll blow the show up.’”

RELATED: What Mr Turnbull said on Q&A

Mr Turnbull was nearly silent in the lead-up to the by-election — he sent just one tweet in support of Mr Sharma, back when he first became the Liberals’ candidate — but that restraint was not been matched by his son.

Speaking to Triple J radio the week before the vote, Alex Turnbull launched a scathing attack on the Liberal Party’s right wing, saying a big part of his father’s record was “fighting the good fight against the crazies”.

Asked to whom he was referring, he proceeded to list the top five “crazy” MPs and senators by name, with Tony Abbott in first place. He described Mr Abbott as “a singularly destructive human being”.

RELATED: Alex Turnbull names and shames Liberal ‘crazies’

He appeared to have some sympathy for Mr Morrison, at least, saying he suffered from “the same problem my dad had”.

“He’s got some very, very crazy people to deal with who are not particularly rational political actors,” he said.

“Being the leader of the Liberal Party and being sane is like being Bruce Willis in a Die Hard movie. It’s always crazy and bad but hopefully you come out and get some stuff done.”

He said his intervention in the by-election campaign had nothing to do with his father, who did not approve of his stance but was “dealing with it”.

“He’s out of office, I’m a private citizen, we can both do as we please,” he told the ABC, insisting he was “absolutely not” doing Mr Turnbull’s dirty work.

Meanwhile, two days before the by-election, the former prime minister himself mysteriously liked a tweet expressing support for Dr Phelps.

“Back handing out policy info and how-to-vote cards for Kerryn Phelps at Waverley Oval pre-polling station. No longer wondering ‘Where’s Malcolm?’ Just hoping for a strong independent win on Saturday,” the tweet from a campaign volunteer said.

A photo of a cardboard cutout of Mr Turnbull, asking ‘Where’s Malcolm?’, accompanied it.

The like was undone within minutes, and no longer appears on Mr Turnbull’s feed.