Sally Bercow's tweets have more readers than some newspapers, a court has been told.
As the libel case brought by Lord McAlpine got underway, the High Court heard the Speaker's wife was not "some kitchen table blogger''.
The former Conservative party treasurer is seeking damages over a posting on Twitter which he says meant that he was a paedophile who was guilty of sexually abusing boys living in care.
Bercow has always denied that her November 4 tweet, "Why is Lord McAlpine trending? *Innocent face*'', was defamatory.
McAlpine's QC, Sir Edward Garnier, told Mr Justice Tugendhat that Ms Bercow had 60,000 followers so her readership was bigger than some local newspapers.
"We are not talking about some kitchen table blogger addressing perhaps herself and one other person.
"We are talking about a pretty widespread readership.''
Sally Bercow was not in court on Tuesday
Neither McAlpine nor Bercow were in court for the peer's contested application for the trial to be split in two, with the first hearing deciding the meaning of the tweet and, if that went in his favour, a second hearing on the appropriate level of damages.
Garnier said that the sooner the meaning was fixed upon the better.
"There will be a huge saving of time and costs and it will allow the parties to get this matter behind them and get on with the rest of their lives however they choose to lead them.''
Bercow's tweet followed a Newsnight report that wrongly implicated McAlpine in child sex abuse allegations.
In February, the peer, who has already received six-figure payouts from the BBC and ITV, announced he was dropping defamation claims against Twitter users with fewer than 500 followers and instead asked for a charitable donation to BBC Children In Need.