Mrs Rooney, the wife of Wayne Rooney, accused Mrs Vardy, who is married to city-born striker Jamie Vardy, of leaking “false stories” about her private life to the media in October 2019, after she said she carried out a months-long “sting operation”.
The wife of former England star Wayne Rooney was dubbed “Wagatha Christie” when she publicly claimed Mrs Vardey shared three fake stories she had posted on her personal Instagram account with The Sun newspaper.
The fake stories included Mrs Rooney travelling to Mexico for a “gender selection” procedure, her planning to return to TV, and the basement flooding at her home.
Mrs Rooney wrote: “I have saved and screenshotted all the original stories which clearly show just one person has viewed them.
“It's .......... Rebekah Vardy's account.”
Mrs Rooney's post was widely shared and heavily parodied on social media at the time, including by the Twitter account of Jeremy Corbyn, then-leader of the Labour Party.
Mrs Vardy, who is married to Leicester City striker Jamie Vardy, denies the accusations and is suing Mrs Rooney for libel.
Under English defamation law, the burden of proof now will be on Mrs Rooney to prove that her post was “substantially true”.
Now the full trial is expected to begin at London's Royal Courts of Justice following months of preliminary hearings - none of which have been attended by either Mrs Vardy or Mrs Rooney.
The case first went to court in November 2020, with a judge finding that Mrs Rooney's post “clearly identified” Mrs Vardy as being “guilty of the serious and consistent breach of trust”.
The judge, now Lord Justice Warby, also said that “the element of suspense introduced by the multiple dots seems to me designed to raise expectations of a dramatic revelation”.
Since then, several hearings have taken place to prepare for the trial, including one where texts between Mrs Vardy and agent Caroline Watt emerged, in one of which Mrs Vardy called someone a “nasty bitch”.
In February, Mrs Rooney's barrister David Sherborne told the High Court that a “series of unfortunate events” have happened over the evidence in the case, notably Ms Watt's phone falling into the North Sea.
Mrs Vardy's lawyers have said she has “nothing to hide”.
Most recently, the High Court was told by Mr Sherborne that Mrs Vardy “appears to accept” that Ms Watt was the source of leaked stories about Coleen Rooney that were published in The Sun newspaper.
Hugh Tomlinson QC, for Mrs Vardy, told the court that his client's new witness statement did not contain “any change whatever in the pleaded case”.
Ms Watt had been due to give evidence in the trial, but was recently found to be “not fit” to take part, also withdrawing her written evidence.
Mr Tomlinson said: “We simply don't know what the true position is in relation to Ms Watt... She's not communicating with anybody.”
The trial in front of Mrs Justice Steyn is expected to last seven days.