Tommy Robinson says he has been told to hand himself in to a police station where he expects to be arrested ahead of a planned march for thousands of people in London.
Supporters of the far-right activist, whose real name is Stephen Yaxley-Lennon, are due to hold a demonstration on Saturday, which is expected to be met with a counter-protest from Stop the War campaigners.
Robinson posted a video on X to say he was going to attend Folkestone police station at 3pm on Friday, but the reasons why he has been told to surrender himself are unclear.
It follows his arrest in July at a port in Kent where he was accused of "frustration" of police counter-terrorism powers.
At the time of his arrest, Kent Police said a 41-year-old man was detained by officers under Schedule 7 of the Terrorism Act 2000 at the Channel Tunnel in Folkestone.
Under schedule seven of the Terrorism Act, police are allowed to stop anyone passing through a UK port "to determine whether they may be involved or concerned in the commission, preparation or instigation of acts of terrorism".
The person who is detained can be held for up to six hours, is legally obliged to answer questions and must provide the password or Pin for electronic devices, or be held to have committed a criminal offence if they refuse.
Robinson said he objected to a request from police for the Pin to his phone because there was privileged information on the device relating to an ongoing High Court case.
He is currently facing jail after he was issued with a contempt of court claim against him following the airing of a film at a protest in central London.
Robinson is alleged to have breached a 2021 High Court order barring him from repeating libellous allegations against a Syrian refugee who successfully sued him.
It is understood the airing of a film, titled Silenced, at a demonstration in Trafalgar Square in July is one of six actions claimed to have breached the injunction between June and July this year.
The film is also pinned to the top of his X account.
The political campaigner is due to appear at Woolwich Crown Court on Monday for a two-day hearing in relation to the alleged contempt of court.
He was released on unconditional bail in July and subsequently left the country, with Adam Payter, representing the Solicitor General, telling the High Court that there "was nothing to prevent him from doing so".
Mr Justice Johnson issued a warrant for Robinson's arrest but ordered that it not be carried out "until early October" to allow Robinson time to indicate that he would attend the next hearing voluntarily or to apply to "set aside" the warrant.
Robinson posted a video of himself arriving at Luton Airport on October 20 and said he was surprised he had not been arrested.
The activist has applied to set aside the warrant and a ruling has not yet been made on the application.
Under the 2021 court order, Robinson was barred from repeating allegations he made against Syrian refugee Jamal Hijazi.
Mr Hijazi successfully sued Robinson after the then-schoolboy was assaulted at Almondbury Community School in Huddersfield, West Yorkshire, in October 2018.
After a clip of the incident went viral, Robinson made false claims, including about Mr Hijazi attacking girls in his school, leading to the libel case.
Mr Justice Nicklin ordered Robinson to pay Mr Hijazi £100,000 in damages and his legal costs, as well as making the injunction preventing Robinson from repeating the allegations he made against the then-teenager.
