Mr Lehrmann has launched defamation action against Network Ten and News Life Media, the News Corp Australia company behind News.com.au, over their coverage of rape allegations made by Ms Higgins.
On Tuesday afternoon, his lawyers filed statements of claim in the Federal Court against the media outlets. Lisa Wilkinson, host of Channel Ten show The Project, and News political editor Samantha Maiden have also been sued.
Ms Higgins accused Mr Lehrmann of raping her inside the Parliament House office of then-minister Linda Reynolds, who they both worked for, in 2019.
On Tuesday evening, Ms Higgins said she would give evidence at the defamation hearings if required.
"Following recent developments, I feel the need to make it clear if required I am willing to defend the truth as a witness in any potential civil cases brought about by Mr Lehrmann," she posted on Twitter.
He has always denied the allegation and maintained the pair never had any sexual interaction.
In his Federal Court lawsuit against Ten, he alleges he was defamed by three publications broadcast on The Project and 10 play on February 15, 2021 in which Wilkinson interviewed Ms Higgins.
Two News articles written by Maiden and published on the same day have been cited in the second defamation suit.
Mr Lehrmann says he was identifiable despite not being named in the reports which falsely claimed he raped Ms Higgins and that he continued to do so when she woke up crying, asking him to stop.
The broadcasts also contained the false claims he crushed himself against Ms Higgins, bruising her leg, and left her on a couch in a "state of undress", he said.
"(Ten, Wilkinson, News and Maiden) were recklessly indifferent to the truth or falsity of the imputations carried by the matters complained of in publishing the assertions and allegations ... without giving (Mr Lehrmann) a reasonable opportunity to respond," he wrote in documents filed with the court.
"(Mr Lehrmann) has been greatly injured in his personal and professional reputation and has been and will be brought into public disrepute, odium, ridicule and contempt."
Wilkinson and Maiden had been "fighting" over exclusive access to the story to win a Walkley award, exploiting the allegations for their own personal gain, he alleged.
He is seeking damages, including aggravated damages, and interest against the media outlets and injunctions barring them from publishing further reports on the rape claims.
He has also sought permission from the court to extend the one-year limitation period typically imposed for defamation proceedings up until the date he filed the lawsuits.
If Mr Lehrmann fails at this bid and a judge determines that the former staffer took too long to commence the proceedings, they will be dismissed.
Mr Lehrmann's criminal trial in the ACT Supreme Court was derailed in October because of juror misconduct and the prosecutor later dropped the charges due to the impacts a second trial would have on Ms Higgins' mental health.
Sydney law firm Mark O'Brien Legal is representing Mr Lehrmann in the defamation proceedings.
The ACT government has launched an independent inquiry into the handling of Ms Higgins' rape allegations by police, prosecutors and a victims' support service.
1800 RESPECT (1800 737 732)
Lifeline 13 11 14
7°C