Federal Liberals are weighing an extraordinary intervention into their South Australia division over fears that senator Alex Antic’s bid for control will stop Opposition Leader Angus Taylor from competing in the state at the next election, as evidence emerges of an attempted purge of high-profile party members.

The party’s federal executive is expected to discuss the prospect of taking over the branch at a meeting on Friday in Canberra, according to several party sources familiar with the talks. The high legal threshold to take over a state division may mean that less drastic action is taken and it is unlikely to be resolved in a day.

Antic’s critics, many within his own Right faction, claim his supporters have been breaching governance rules by overturning the results of annual general meetings and pushing for the expulsion of former foreign minister Alexander Downer, former MP Nicole Flint, and former state MP Vickie Chapman.

All three are viewed as critics of Antic, a far-right senator who consistently votes against Taylor’s wishes in Canberra and has repeatedly opened the door to joining Pauline Hanson’s One Nation. His colleagues fear he is pushing for closer collaboration with Hanson, as suggested by his ally, Barker MP Tony Pasin, who previously called for a seat-sharing deal with Hanson.

Liberals close to Taylor, including party president Tony Abbott, have worked behind the scenes to prevent Antic from becoming South Australian president in an election next month. Moderates and right-wingers fear the prospect of the anti-vaccine, anti-abortion activist, MAGA-loving senator taking control.

But some federal and South Australian MPs hold the view that Antic cannot be talked out of his mission to upend the party. They will push for the federal branch to take the reins in South Australia, as the party did after the NSW division failed to lodge applications for council candidates.

The threshold for federal intervention is difficult to meet. Even some of Antic’s fierce critics think it probably cannot be reached unless Antic escalates his plans. But those pushing for the drastic move will allege that Antic’s forces are acting in a reckless manner that must be stopped.

In a series of messages obtained by this masthead, Antic’s leading numbers man, Dom Gelonese, pushes powerbrokers to kick out former MPs.

“Downer needs to be expelled from the SA Liberal Party. The process to do this should be looked into ahead of time,” Gelonese wrote last year, citing a famous meeting in which the former ambassador to the UK discussed with FBI agents the prospect of Russian meddling in the 2016 US presidential election.

“We need to clean our house and remove those involved in fraudulent election interference activity.”

Gelonese has also been pushing to remove former MP Nicole Flint, who is mulling a preselection challenge against Pasin.

Talking about former state attorney-general and long-time Moderate Vicki Chapman, Gelonese said: “We need to pull the trigger on expelling Vicki.”

“My understanding is that now they can’t federally intervene, so what’s the reason for not pulling the trigger?” he said in November

Gelonese’s campaign has been resisted by the remaining South Australian Liberals who are not aligned with Antic. They include serving party president and federal senator Leah Blythe. Blythe has fallen out with Antic over the past year, particularly over her failure to cross the floor on the post-Bondi hate crimes legislation.

Antic’s supporters allege that Blythe is pushing against Antic’s election so that she can avoid losing to a supporter of Antic at her upcoming preselection. They claim she is attempting to fast-track her preselection to protect herself.

Gelonese, responding to questions from this masthead, did not deny the push to expel high-profile members.

“No party representative is immune from oversight when their conduct warrants it. Questions of expulsion belong inside the party, not splashed across the media by the professional victim-class within it,” he said, claiming Antic’s opponents were lashing out because they were losing.

“After a string of spectacular AGM thrashings, their grip is collapsing, so they’re frantically manufacturing excuses for federal intervention. Nothing says ‘we respect democracy’ quite like trying to overturn it the moment you lose.”

“These frantic attacks on a grassroots member are pure projection from people comprehensively rejected by the membership.”

If the party is successful in stopping Antic from winning the presidency, it should avoid the need to launch a federal intervention. Several of Antic’s colleagues said the easier course of action would be to push Antic out of the parliamentary party, but Taylor has previously been resistant to contemplate such a move.

The saga surrounding Antic has turned into a test of Taylor’s grip on the party and a demonstration of the depths of the party’s administrative troubles at state level, bar the successful LNP in Queensland.

“If he’s not going to assist the party to do what it needs to do to win the next election, he should leave,” one senior right-wing MP said of Antic on Thursday.

Antic, who did not respond to questions, has drawn support from One Nation-aligned online campaigners including 2WorldsCollide podcaster Sam Bamford, who is campaigning against Andrew Hastie over his stance on war crimes, and anti-abortion activist Joanna Howe. Several of Antic’s backers have been caught handing out flyers for One Nation and saying publicly at party meetings that they would be voting for One Nation and donating to Hanson.

Antic invited Howe to an August 6 meeting of the party’s women’s council, leading to a fight with party moderates and a mass walkout.

Howe slammed Blythe for not taking up the fight on abortion, which former party leader Peter Dutton fought to keep off the agenda in Canberra.

“I had hoped that she would speak up for babies in the womb,” Howe said at the meeting. “What is the point of power if you don’t use it?”