Brittany Higgins and her husband left 'fearful' after stranger made menacing threat made to couple and their dog

A man will have to wait to learn his fate after he threatened to kill former political staffer Brittany Higgins, her husband, and the couple's dog in a nasty online rant.

David William Wonnocott wore a blue Hawaiian shirt and black pants as he faced Lismore District Court on Monday after pleading guilty to using a carriage service to threaten to kill and using a carriage service to menace or harass.

The 49-year-old targeted Ms Higgins and NSW politician Alex Greenwich in vicious online attacks which were deemed to pose a serious threat to their safety.

He was arrested by the Terrorism Investigation Squad on April 19 last year after police allegedly discovered 49 threatening and offensive messages sent from linked accounts.

Police discovered Wonnocott had used one of the social media accounts to send messages to Ms Higgins' now-husband David Sharaz which contained death threats against him, Ms Higgins, and the couple's beloved cavoodle.

The court heard the couple 'became fearful for their safety' after the messages.

The Banora Point resident also admitted he had sent menacing messages to openly gay Sydney MP Alex Greenwich in a separate incident.

Judge John Pickering noted Wonnocott had a 'seemingly highly entrenched view of disapproving of the lesbian, homosexual community'.

Wonnocott was due to be sentenced on Monday, however his lawyer asked the court for an adjournment to allow her to obtain a psychiatric report.

Judge Pickering adjourned the matter until November.

Ms Higgins has been subjected to a torrent of online abuse since she publicly alleged she had been raped by a colleague in Parliament House in 2019.

Her fellow political staffer Bruce Lehrmann pleaded not guilty to the sexual assault in 2021 but the trial was later abandoned due to juror misconduct.

The Director of Public Prosecutions declined to pursue a retrial out of concern for Ms Higgin's mental health.

Mr Lehrmann was recently ordered to pay millions after he brought a failed defamation lawsuit against Network 10 and journalist Lisa Wilkinson.

He claimed he had been defamed by an interview between Ms Wilkinson and Ms Higgins on Network 10's The Project in 2021.

In April, Justice Lee dismissed the case and determined Mr Lehrmann had, on the civil standard of the balance of probabilities, raped Ms Higgins in Parliament House in 2019.

Six weeks later, Ms Higgins and Mr Sharaz were married at The Valley Estate in Currumbin on Queensland's Gold Coast.

After years of intense media scrutiny, the couple have moved to France with their cavoodle Kingston in search of a fresh start.

On Sunday night, the couple announced they are now expecting their first child.