Linda Reynolds sued Ms Higgins over a series of social media posts the ex-Liberal senator believed damaged her reputation.
A Western Australian Supreme Court in August found the posts were defamatory and awarded damages of $315,000 plus $26,109 interest to Ms Reynolds.
Ms Higgins was also ordered to pay 80 per cent of Ms Reynolds' yet-to-be-determined legal costs, but is appealing elements of the judgment.
She is challenging the damages and costs orders, and the finding that she breached a 2021 deed of settlement between the pair by referring to herself as a "defamation victim" in an Instagram post.
Ms Reynolds confirmed on Tuesday that she has filed a creditor's petition in the Federal Court, claiming Ms Higgins "failed to comply" with a bankruptcy notice issued to her several weeks ago.
"It is unfortunate that I have to take this step in this long-running saga," the former parliamentarian said in a statement.
"As I have said, this is conduct which comes as no surprise to me however what should be plain now is that I am committed to seeing this through to the end."
Federal Court records show the former senator filed the bankruptcy proceedings against Ms Higgins on Friday.
Ms Higgins' husband David Sharaz has also been served with similar bankruptcy proceedings by Ms Reynolds.
The ex-political staffer apologised to Ms Reynolds following the former defence minister's high-profile five-week defamation trial victory in September 2024.
The trial centred on a tweet Ms Higgins and her husband published in January 2022, which carried imputations that Ms Reynolds pressured Ms Higgins not to proceed with a sexual assault complaint and that she was a hypocrite in her advocacy of gender equality and female empowerment.
Justice Paul Tottle found Ms Higgins' social media posts were defamatory after they implied Ms Reynolds engaged in a campaign of harassment against Ms Higgins, mishandled her rape allegation and engaged in questionable conduct during Bruce Lehrmann's aborted criminal trial for rape.
The 360-page judgment made factual findings about events involving the pair, including Ms Higgins' alleged 2019 rape and that Ms Higgins made 26 false or misleading statements in media interviews.
She alleges former co-worker Lehrmann raped her in the senator's ministerial suite, a claim he has always denied.
His criminal trial was aborted due to juror misconduct.
A Federal Court judge overseeing a defamation case launched by Lehrmann against Network Ten found Ms Higgins was, on the balance of probabilities, raped by her former colleague in the office.
Lehrmann is appealing that finding.
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