Barbara Ramjan, the woman who accused Tony Abbott of intimidating her physically at Sydney University, is suing the Victorian Liberal Party powerbroker, Michael Kroger, and The Australian newspaper, over comments during the recent fallout from the saga.

The defamation action, lodged in the NSW Supreme Court on Monday, has the potential to reopen the debate over the alleged wall-punching incident.

It relates to comments Mr Kroger made about Ms Ramjan on the Bolt Report television show on September 23, two articles that appeared in The Australian the next day, and an interview Mr Kroger gave to Alan Jones, in which he called Ms Ramjan "a nutter" and "a nobody".

In September, an essay by David Marr recounted claims by Ms Ramjan that in 1977, after she beat Mr Abbott for the presidency of the university Student Representative Council, he put his face close to hers and punched the wall either side of her head.

Mr Abbott said at first he had no recollection of the incident and added later that he had no recollection because it never happened.

In the ensuing ruckus, Mr Kroger, who was defending Mr Abbott, accused Ms Ramjan of lying about the alleged punching incident, and also another incident which happened on campus in 1978.

On the Bolt Report, hosted by conservative pundit Andrew Bolt, and the next day for The Australian, Mr Kroger produced a Trotskyist student political newsletter which he said showed that Ms Ramjan had claimed that members of the rival far-left Spartacists on the University of Sydney campus had threatened to kill her.

The Spartacists rejected the claim.

Mr Kroger alleged Ms Ramjan, whose husband is a former Supreme Court judge, had a history of making false complaints against political opponents.

On Tuesday, after the discussion Mr Kroger had with Jones on his 2GB radio show, Jones apologised after being contacted by Sydney lawyer, Chris Murphy, a mutual friend of both Jones and Ms Ramjan.

Abbott Accuser To Sue Liberal Party Powerbroker