Amber Harrison has been ordered to pay all Seven West Media's legal costs after a judge found she made allegations she could not substantiate and acted unreasonably in her battle with the company.
The ex-lover of Seven boss Tim Worner faces a bill which could total hundreds of thousands of dollars after she was ordered to pay costs on an indemnity basis - a higher rate than usually applies in legal disputes.
But Ms Harrison says she won't cough up.
"I'm not going to pay it," she told the Nine Network.
"I can't pay it. They knew it would bankrupt me and the Supreme Court of NSW has helped them do it."
Ms Harrison, a former Seven employee, had been embroiled in a bitter battle with the broadcaster since December when she publicly revealed details of the affair and other confidential information.
Justice John Sackar said Ms Harrison decided to contest Seven's claim and run a cross-claim "mounted on allegations she could not substantiate".
She "continued to run this case in the face of adverse interlocutory findings, settlement offers, and a complete absence of evidence", he said in his NSW Supreme Court judgment on Monday.
"This conduct is in my view unreasonable, resulting in (Seven) incurring unnecessary and significant legal costs."
The media company had sought a permanent gag order preventing Ms Harrison from leaking company documents, detailing the affair or launching any legal proceedings.
It contended that her social media posts had breached her employment contract and a deed in which the company agreed to pay her $427,418 in instalments for her silence.
Days before the hearing was due to start on July 10, Ms Harrison abandoned her fight against Seven, which then sought various orders, including all its costs.
The judge said "numerous epithets" had been used to describe Ms Harrison and her motivations.
"I do not feel the need to join in the histrionics," he said.
"The evidence on any view is relevantly clear, unequivocal and largely uncontested.
"She had and has engaged in numerous breaches of the deed and employment contract, and these breaches have been persistent and flagrant."
The judge said the proceedings had, from the outset, been engulfed in "a vitriolic atmosphere".
"The allegations from both sides, whether entirely true or not, have often been personal, scandalous, and sadly ripe for media and public consumption."
Ms Harrison's decision to persist in running a case "without any admissible evidence to rely upon reflects a real disregard for any adverse costs consequences that naturally flow from such conduct".
The former executive assistant previously told the judge an indemnity costs order would be "punitive and pointless" and would drive her to bankruptcy.
Ms Harrison said she was a victim "of brutal corporate bullying and lawfare".
Seven, in a short statement, said: "Seven West Media looks forward to putting this matter behind us."