Mr Lobov claims that he has been the subject of a barrage of harassing, intimidating and defamatory posts by McGregor on his Twitter account
The case came before Mr Justice Garrett Simons, who said that he will rule on an application brought by Mr Lobov, which is opposed by Mr McGregor, for orders including an injunction requiring Mr McGregor to remove the material complained on Friday morning.
In his action Mr Lobov claims that he has been the subject of a barrage of harassing, intimidating and defamatory posts by McGregor on his Twitter account.
Mr Lobov claims that the most damaging post about him on Mr McGregor's Twitter account, @The NotoriousMMA is where he is allegedly referred to in a song sung by Mr McGregor as being a "rat".
The High Court heard that Mr Lobov claims that the defendant's posts about him arise from other legal proceedings brought by him against Mr McGregor over a purported multi-million Euro whiskey deal.
As a result of the posts, Mr Lobov seeks an order under Section 33 of the 2009 Defamation Act prohibiting Mr McGregor from publishing any further posts similar to those allegedly published by Mr McGregor on Twitter on November 26th last.
The 36-year-old Russian national also seeks an order requiring the defendant, or any other person who has notice of the proceedings to cease and desist from making any similar posts on social media to those complained of.
Mr Lobov, who is represented by represented by Andrew Walker SC instructed by solicitor Dermot McNamara, further seeks an order requiring the defendant to take down and remove any of the allegedly defamatory posts on Twitter or on any other form of social media.
Mr McGregor was not present in court on Thursday, morning but lawyers on his behalf opposed the application.
His counsel Remy Farrell SC, instructed by solicitor Michael Staines said the matter, including the application for a Section 33 order, was "wholly unsustainable", raised issues concerning the freedom of speech and expression and that there were other alternative remedies available to Mr Lobov.
He added that both parties in this dispute are MMA fighters and that Mr Lobov was not happy that Mr McGregor was being mean in the posts about the plaintiff.
Counsel said that both were MMA fighters, and in that sport "thrash talk" between rivals was common place.
Counsel accepted that while Mr McGregor has not yet sworn a statement in reply to the application before the court, which he added Mr McGregor is seeking time to do.
Counsel said that the context of the comments complained is relevant, given that both parties are involved in a dispute over the sale of a whiskey brand, which remains pending before the courts.
Arising out of that action, counsel said Mr McGregor may well have a defence to the claim of defamation including that his remarks are the truth and can be justified.
Seeking the injunction Mr Walker said that it is his client's case that the defendant has no defence to the application, and that the orders sought by Mr Lobov should be granted by the court.
His client has not received any response from Mr McGregor regarding his complaints about the posts, nor a sworn statement formally opposing the injunction application.
In his submissions Mr Walker did not accept that the comments made were merely unfair and upsetting to his client.
The "uncontrolled" posts by Mr McGregor about his client, Mr Walker said, are highly damaging to Mr Lobov and are also in breach of Twitter’s own code of conduct.
In reply to the judge, Counsel said they were much more serious and damaging to his client compared the sort of posts one might see on social media when a professional soccer player transfers to a rival club.
Counsel said that there could well be another barrage of statements from Mr McGregor about his client, irrespective of what the court decides in this aspect of the proceedings.
Mr Lobov has brought proceedings where he claims that on November 26th last several posts were put on Mr McGregor's account by way of voice note where it is alleged the defendant sings "Artem is ra-at nah nah nah nah, hey, nah nah nah nah hey rat" repeated 12 times.
The defendant has also allegedly referred to Mr Lobov as being a rat in other posts, posted between late November and December 15th last on his Twitter account, which has 9.7 million followers.
The court also heard that a picture of Mr Lobov superimposed on a packet of raw sausages was also posted on Mr McGregor's Twitter account.
In other messages posted on the account it is claimed that Mr McGregor calls Mr Lobov a little blouse, a turn coat, an uncooked sausage, makes references to court proceedings the parties are in, and challenges the plaintiff to a fight.
Mr Lobov also claims that as part of the campaign against him on Twitter and Instagram Mr McGregor's father Tony McGregor also sent him pictures of a rat, a snake and rats.
Mr Lobov sought an undertaking from Mr McGregor to cease and desist from posting such material.
Mr Lobov's lawyers received no reply from the defendant.
The court heard that the parties have known each other for many years, and had been close friends and sparring partners.
In proceedings that came before the Commercial Court earlier this month Mr Lobov claims that Mr McGregor who, along with two other shareholders, sold the "Proper No 12" whiskey brand for US$600m (€584m) to Proximo Spirits in 2021
The deal reportedly netted Mr McGregor US$130m (€123m), making him the highest earning sportsman in the world last year.
Mr Lobov claims Conor McGregor told him that "remember 5pc is yours, no matter what" when the pair discussed the future of a new brand of Irish whiskey backed by McGregor.
Mr Lobov, seeking specific performance of an oral agreement he says the two men made when they met in the SBG gym, Naas Road, Dublin, in September 2017.
The court heard that Mr Lobov was offered €1m by Mr McGregor, but had refused the offer.
Mr McGregor denies Mr Lobov's claim and says that in one message sent by him (Lobov) he stated that he did not want anything from the deal.
However, Mr Lobov failed to get his case admitted to the fast-track Commercial Court list due to delay in bringing the case which now goes through the normal High Court list.