Ms Rooney, 35, accused Ms Vardy, 39, of leaking “false stories” about her private life in October 2019 after carrying out a months-long “sting operation” which saw her dubbed “Wagatha Christie”.
The wife of former England star Wayne Rooney claimed her fellow footballer’s wife leaked fake stories she had posted on her personal Instagram account to the newspaper.
She wrote on Instagram and Twitter at the time: “For a few years now someone who I trusted to follow me on my personal Instagram account has been consistently informing The Sun newspaper of my private posts and stories.
“I have saved and screenshotted all the original stories which clearly show just one person has viewed them. It’s.......... Rebekah Vardy’s account.”
Ms Vardy, who is married to Leicester City striker Jamie Vardy, denies the accusations and is suing Ms Rooney for libel.
At a hearing on Friday, Ms Vardy’s lawyers asked the High Court to throw out parts of Ms Rooney’s defence, including allegations of Ms Vardy’s close relationship with The Sun and benefits she received.
Hugh Tomlinson QC, for Ms Vardy, said: “The purpose of this application is to clear away what we say is a mass of irrelevant or peripheral material to save time and costs.”
Mr Tomlinson denied Ms Vardy wanted those parts of the defence thrown out because they would be embarrassing for her.
“If necessary she will deal with it but we say it is not necessary and will be a waste of everybody’s time,” he added.
The barrister argued the central issue was whether Ms Vardy was leaking posts from Ms Rooney’s Instagram and that the other issues would not be necessary.
In his written submissions, Mr Tomlinson said most of the claims made by Ms Rooney’s lawyers were in dispute and denied.
The move to throw out part of the defence was opposed by Ms Rooney, with her barrister David Sherborne arguing the “exceptionally close relationship” Ms Vardy is claimed to have had with The Sun is a key part of the case.
In written submissions, Mr Sherborne said Ms Vardy had a “habitual practice” of providing private information to the press to promote her profile.
He said: “The timing of positive coverage of the claimant in The Sun was strikingly close to the publication of other articles ... that were leaked from the defendant’s private Instagram.
“This supports the inference that the claimant was benefitting from the leak of private information about the defendant to the newspaper.”
Mr Sherborne added that Ms Vardy used her close relationship with The Sun or its journalists “for the purposes of promoting or financially exploiting her public profile”.
The barrister later claimed Ms Vardy would receive a split of commission and revenue for stories given to The Sun through the Front Row Partnership, a PR agency where Ms Vardy was a client.
Ms Vardy has denied any knowledge or authorisation of passing on private information.
On Friday, the High Court also heard mediation took place between the two women but was unsuccessful.
Ms Vardy has also applied for summary judgment – a legal step which would see that part of the case resolved without a trial – in relation to Ms Rooney’s claim Ms Vardy leaked a story to The Sun about her returning to TV presenting.
Ms Rooney said she blocked everyone except Ms Vardy from seeing her Instagram stories between 1 September and 4 October 2019 before posting a selfie with text reading “easing my way back into work!! TV decisions today” on 25 September.
A story reporting her desire to revive her TV career appeared on The Sun’s website three days later, Ms Rooney claims.
However, Ms Rooney said she “invented” the story as part of her investigation to discover the source of the leaks and had no intention of entering into more television work.
Ms Rooney has also said she planted stories about her travelling to Mexico to “see what this gender selection is all about” and the basement flooding in her new house.
Ms Vardy sued Ms Rooney last June, claiming she “suffered extreme distress, hurt, anxiety and embarrassment as a result of the publication of the post and the events which followed”.
In her written case against Ms Rooney, Ms Vardy’s lawyers said the abuse she received made her “feel suicidal”, adding: “She suffered from severe panic attacks and anxiety which manifested in being scared to leave her house.”
Ms Vardy claimed her husband Jamie was targeted during football matches, with opposition fans chanting “your wife is a grass” for up to five minutes at a time.
The hearing before Ms Justice Steyn continues.
Additional reporting by PA