Network Ten allegedly owes more than $723,000 to television personality Lisa Wilkinson who claims the broadcaster has refused to pay her legal bill after being sued by Bruce Lehrmann.

The former Liberal staffer has hit Ten and Wilkinson with a Federal Court lawsuit accusing them of defamation through a June 2021 interview on The Project with Brittany Higgins over rape allegations in Parliament House.

During the defamation proceedings, Wilkinson opted to hire separate legal representation than Ten. 

In a NSW Supreme Court lawsuit filed on Thursday, she alleges the television network has refused to pay her legal bills after she retained Gillis Delaney Lawyers partner Anthony Jefferies and barrister Sue Chrysanthou SC in the defamation case.

Wilkinson says her legal costs up to May 30 this year were around $353,000 and that she tallied up a further $370,000 in costs from that date until September 20.

She says Ten is vicariously liable to pay these legal expenses as she is an employee of the company.

In court documents seen by AAP, Wilkinson says Ten first claimed it was not liable to indemnify her for her legal costs given she had separate counsel.

After receiving advice from high-profile barrister Bret Walker SC, Ten allegedly changed its position, saying it only had to pay the journalist’s costs after the lawsuit had been concluded.

Wilkinson claims the broadcaster changed tack again after her lawyers pointed out the “vices” of this position, instead arguing about the details and reasonableness of her legal invoices.

“(Ten) has still not paid (Wilkinson) any amount in respect of any item of work or any dollar of cost and expense described in the invoices and narrations provided to (Ten),” she wrote.

The firm had also not pointed out which legal costs itemised on her invoices were unreasonable in the way she had defended the defamation case.

A spokesperson from Network Ten said that Wilkinson’s legal team had asked for a lot of money.

“The lawyers engaged by Lisa Wilkinson have issued invoices for a very substantial amount of money, in excess of $700,000, and in good governance these need to be justified through due process,” she said.

 “In the meantime, Network Ten’s focus is on defending the defamation claim brought by Bruce Lehrmann.”

Mr Lehrmann was accused of raping Ms Higgins in the Parliament House office of their then-boss, defence industry minister Linda Reynolds in 2019.

He has always denied the allegations.

Mr Lehrmann has also sued the Australian Broadcasting Corporation for defamation over a joint speech by Ms Higgins and former Australian of the Year Grace Tame at the National Press Club, which was broadcast live on the ABC in February 2022.

The former Liberal staffer claims the reports defamed him, destroying his reputation.

His criminal trial in the ACT Supreme Court was derailed by juror misconduct and prosecutors did not seek a second trial due to concerns over Ms Higgins’ mental health.

A landmark report into the ACT legal system and the Higgins case by Walter Sofronoff KC made damning findings against now ex-director of public prosecutions Shane Drumgold over his conduct during the case.

Mr Drumgold has taken legal action against both the ACT government and the board of inquiry headed by Mr Sofronoff in an attempt to overturn these findings.