Jackie O Henderson privately told friends she had decided not to return to her top-rating radio show just days after her explosive on-air clash with co-host Kyle Sandilands, newly revealed text messages show, before claiming she had not quit and launching a multimillion-dollar legal battle alleging she was unlawfully sacked.

The exchanges were aired in the Federal Court on Monday as lawyers for Ms Henderson and her former employer, the Australian Radio Network, fought over access to confidential communications, including private texts, boardroom discussions and legal advice exchanged in the days leading up to her contract termination.

ARN’s own private communications also came under scrutiny during the interlocutory hearing with Henderson’s lawyers fighting to obtain access to secret boardroom discussions and directors’ WhatsApp messages.

Ms Henderson and her company, Henderson Media, are suing ARN Media and its subsidiary Commonwealth Broadcasting Corporation, alleging unlawful adverse action and breach of contract.

ARN denies wrongdoing, arguing Ms Henderson’s refusal to continue presenting The Kyle and Jackie O Show alongside Mr Sandilands entitled it to terminate her agreement.

The pair’s 25-year professional partnership spectacularly imploded after Mr Sandilands attacked Ms Henderson’s interest in astrology during their February 20 broadcast, describing her as “almost unworkable” and “off with the fairies”.

When Ms Henderson told him she was offended, he replied: “Well, too bad if you are.”

Ms Henderson subsequently stopped presenting the program.

On Monday, ARN’s lawyers took the court through a series of private messages exchanged in the days after the confrontation.

In a February 23 exchange with two friends, Ms Henderson wrote: “I’m taking time off the show. I think I might be done or at least working with Kyle.”

“I’m speaking with a lawyer at 1pm to get an idea of where I stand.”

That same day, Ms Henderson’s manager, Gemma O’Neill, messaged her about a conference call with lawyers.

“Reminder, I’ll call you at 1pm once I have Jennifer on the line,” Ms O’Neill wrote.

“She’s also having her colleague join the call, who is the specialist with Workplace Law and Fair Work.”

During that meeting, Ms Henderson texted her friend Justine Corry: “I’ve made the decision to not return to the show, just on the phone to the lawyer to write up a legal letter. We’ll see what happens from here.”

However, the court also heard Ms O’Neill had given evidence that Ms Henderson had resolved to present another program at a different time of day.

On February 24, Ms Henderson told her personal assistant, in another private text message: “I just don’t want to work with Kyle anymore.”

That same day, Ms O’Neill was working with Ms Henderson’s lawyers on a formal complaint to ARN.

“I think best if I come over to meet and go through the letter with you right at the end of the day tomorrow to give Jennifer, Peter, and I the time to get it all perfect,” she texted Ms Henderson. The court heard Jennifer and Peter were solicitors.

By the following morning, Ms Henderson had drafted her own proposed public statement and sent it to Ms O’Neill for consideration.

“After a great deal of thought, I made the decision to step away from the Kyle and Jackie O show,” it began.

“This wasn’t a choice made in response to an isolated moment.”

On February 26, Ms Henderson’s lawyers sent ARN a formal complaint alleging persistent bullying and raising workplace safety concerns.

The letter stated that “our client cannot continue to work with Mr Sandilands”, although Ms Henderson indicated she was willing to present another program in a different timeslot.

ARN interpreted the letter as a refusal to fulfil her broadcasting contract.

Ms Henderson had told her personal assistant that day she had another potential opportunity.

“It’s not like I won’t have a job. I have an offer anyway. There’s a safety net,” she wrote.

ARN barrister Peter Gaffney took Justice Ian Jackman through the private messages while arguing Ms Henderson and Ms O’Neill had put their reasons for sending the formal bullying complaint in issue.

ARN argued the exchanges showed Ms Henderson had already decided not to return to the breakfast show before lodging the complaint.

Mr Gaffney also argued that some otherwise confidential communications involving Ms Henderson, Ms O’Neill and their lawyers should be disclosed because the pair had relied on their reasons for sending the letter.

Ms Henderson’s lawyers opposed the move, maintaining that explaining why the complaint was sent did not mean their confidential legal discussions had lost protection.

The court also heard Ms Henderson and Ms O’Neill later considered an alternative role proposed by ARN.

Correspondence discussed in court showed Ms O’Neill formally declined the proposal on Ms Henderson’s behalf on March 30, after explaining why it was considered unsuitable.

On March 3, ARN terminated Ms Henderson’s lucrative broadcasting contract.

Ms Henderson issued a public statement on March 6 saying “I want to make one important point very clear: I did not quit or resign”.

Meanwhile, ARN is claiming legal professional privilege over messages between ARN directors and exchanges in a WhatsApp group called ARN NEDs, used by the company’s non-executive directors.

Ms Henderson’s barrister, Vanja Bulut, is seeking access to a message director Belinda Rowe sent the group on March 3, the day Ms Henderson was sacked.

The court also heard about a separate text exchange that morning between Ms Rowe and ARN chairman Hamish McLennan.

Ms Rowe told the chairman she had spoken to an ARN executive the previous day to follow up on questions she and fellow director Brent Cubis had about interviews with staff and Mr Sandilands.

Mr McLennan replied: “OK thanks. I have to call you in about four hours. Does anything change our discussions?”

Ms Rowe’s response was redacted after ARN claimed legal privilege over it.

The court heard the network’s board met on March 2 to discuss its options.

According to an affidavit from Mr Cubis, he entered the meeting without a firm view about what should happen but subsequently concluded Ms Henderson’s contract had to be terminated.

The following day, legal advice from two law firms – Herbert Smith Freehills Kramer and Arnold Bloch Leibler – was circulated to directors.

ARN chief executive Michael Stephenson prepared a memorandum recommending the company terminate Ms Henderson’s agreement on the grounds that she had indicated she would no longer fulfil her contractual obligations.

A board subcommittee then met, with lawyers present, and approved the proposed course of action.

“It was his recommendation that was actioned by the board, and so he materially contributed,” Ms Bulut said of Mr Stephenson.

The court also examined evidence from director Alison Cameron, who said she was prepared to support terminating Ms Henderson’s contract and issuing a breach notice to Mr Sandilands, provided other directors were satisfied with the legal advice.

ARN’s lawyers insisted the directors had acted for legitimate contractual reasons, not because Ms Henderson had complained about Mr Sandilands or exercised workplace rights.

ARN’s lawyers argued that obtaining and considering legal advice before terminating a commercially significant agreement was an ordinary and responsible step for company directors and disputed the suggestion that referring to legal advice in evidence automatically entitled Ms Henderson to inspect the confidential advice itself.

Another dispute concerned ARN’s investigation into the February 20 confrontation.

The court heard the network’s chief people officer, Ros Reeves, initially proposed an investigation aimed at understanding what happened, hearing different perspectives and strengthening workplace culture.

“The investigation is not intended to be punitive. It is about understanding,” Ms Reeves wrote in a February 21 email.

ARN chief legal officer Jeremy Child subsequently said he arranged the investigation to help the company obtain legal advice.

Ms Henderson’s lawyers questioned whether the investigation had genuinely been conducted for that purpose from the outset.

Under Ms Henderson’s landmark 2023 broadcasting agreement, Henderson Media was entitled to approximately $9.4 million annually plus revenue sharing, according to ARN’s submissions.

The deal was intended to keep Ms Henderson and Mr Sandilands on air until the end of 2035.

Justice Jackman reserved his decision at the conclusion of Monday’s hearing, telling the parties he hoped to deliver a ruling within a couple of weeks.

Ms Henderson’s trial is scheduled to begin in April.