Tommy Robinson has been jailed for 13 months for breaking contempt of court laws with a Facebook Live video.
His sentence can be revealed for the first time after The Independent and Leeds Live fought a reporting restriction put on the case at Leeds Crown Court.
Robinson, whose real name was listed on court documents as Stephen Yaxley-Lennon, was arrested outside the court on 25 May.
He admitted committing contempt of court by publishing information that could prejudice an ongoing trial via a live stream on his Facebook page.
At one point the video was being viewed by more than 10,000 people, as Robinson attempted to film defendants entering the court and discussed the case, which is subject to a separate reporting restriction.
A judge initially banned media reports of contempt proceedings against Robinson over fears it could affect the ongoing trial, but lifted the order after hearing submissions that members of the public and foreign media outlets were publishing inaccurate information.
Supporters of the far-right figurehead have protested over his imprisonment and the reporting restrictions, using them to claim the “establishment” was attempting to silence his views.
Donald Trump Jr, the US President’s son, shared a tweet from a Robinson supporter with the comment “don’t let America follow in those footsteps”, while foreign politicians including Dutch opposition leader Geert Wilders have called for his release.
A “free Tommy” protest is being planned for London’s Whitehall on 9 June, while a petition to free him has reached almost half a million signatures and assistants have directed supporters to donate money for legal fees online.
Robinson made clear that he was aware of the restrictions during the Facebook Live video, as well as the danger of being jailed.