Ms Harkin, who has sat on the state executive, submitted her resignation to the Liberal Party’s Victorian division on Sunday.
From the conservative wing of the party, Ms Harkin has battled internal opponents for years and headed the legal action against the division for giving a $1.55m loan to former leader John Pesutto.
She has been a vocal supporter in the party for upper house MP Moira Deeming. The loan to Mr Pesutto was made to pay his debt to Ms Deeming after he was successfully sued for defamation.
After Victorian Liberal leader Jess Wilson helped install Brian Loughnane as the new federal president over Ms Harkin’s opponent Philip Davis last month, it was hoped that many of the divisions that have dogged the party for years would settle.
While Ms Harkin’s resignation will reignite tensions, some senior members of the party believe it will help the Victorian division move on from those divisions and focus on the November state election.
A senior Liberal figure said it was “no great shock that the person trying to destroy the party by suing it for the last year has finally resigned”.
“The only surprising thing is that she didn’t do so sooner,” he said. “The other litigants should reflect on whether they want to continue to be associated with someone so intent on making life easier for Jacinta Allan and Labor.”
Liberal members suspect Ms Harkin will now join One Nation. The Australian contacted her for comment.
Such a move would come amid a long line of defections to the populist party at the federal and state level, including former Nationals leader Barnaby Joyce, who announced in December he would join Pauline Hanson. Former Liberal senator Cory Bernadi followed suit, joining in February.
The defections come amid a boom in the polls for One Nation, as Liberal and Nationals voters desert the party.
Victorian One Nation candidate Darren Hercus, one of up to 100 candidates the party plans to run across both houses at the upcoming November election, claimed the party had received more than 1000 applications for political candidacy positions including from “doctors and lawyers”.
It follows Rikkie-Lee Tyrrell in 2022 becoming One Nation’s first upper house member of the Victorian parliament.
Ms Harkin, director of education programs and a research fellow at the Institute of Public Affairs, told ABC radio on Friday that a One Nation fundraiser she attended the previous week had a “very high energy and “positive feel”.
“What interested me most was the spread of type of people who were there,” she said. “That was a great interest to me. When we’ve had conversations here about a presumption of people who have lower socio-economic class or lack of academic qualifications or whatever being One Nation supporters, it was definitely not what was in the room.
“High-profile business people, money, just a great spread of ordinary Australians.”
She said a lot of people she spoke with had not been politically engaged before, and were just concerned at the direction … and tenor of the country. “It was very positive. They had a really like a positive energy and vibe in the room.”
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