Image copyright AFP Image caption Robinson was found guilty of interfering with the trial of a sexual grooming gang

Ex-English Defence League leader Tommy Robinson encouraged "vigilante action" against defendants when he filmed them in a Facebook Live, judges have said.

Robinson was found in contempt of court last week over the broadcast, which he made in breach of a reporting ban, outside Leeds Crown Court in May 2018.

Explaining the decision, judge Dame Victoria Sharp said the video could have "seriously impeded" justice over a sexual grooming gang's trial.

His sentencing is expected on Thursday.

In a written ruling, Dame Victoria - President of the Queen's Bench Division of the High Court - gave the reasons why she and Mr Justice Warby had found Robinson guilty.

She said that the 36-year-old, from Luton, had claimed his intention in making the broadcast was to "denounce the media" for their behaviour.

But the judges found Robinson, whose real name is Stephen Yaxley-Lennon, had encouraged others "to harass a defendant by finding him, knocking on his door, following him, and watching him."

This created "a real risk that the course of justice would be seriously impeded", she said.

Image copyright PA Media Image caption Tommy Robinson told the crowd outside the Old Bailey on Friday that he thought the decision was wrong

"All of this has to be assessed in the context of the video as a whole, in which the respondent [Stephen Yaxley-Lennon] approves and encourages vigilante action."

The judges were sure his words would have been understood by "a substantial number of viewers as an incitement to engage in harassment of the defendants", she added.

Dame Victoria said that using the dangers of using "un-moderated platforms" on social media were obvious and that Robinson's conduct created a risk that the defendants would be intimidated.

Mr Robinson's words during the broadcast "had a clear tendency to encourage unlawful physical or verbal aggression towards identifiable targets".

"Harassment of the kind he was describing could not be justified", she said.

Image copyright PA Media

Dame Victoria added that Robinson's Facebook Live could have made the defendants "feel intimidated" which risked having a "significant adverse impact on their ability to participate in the closing stages of the trial."

"That in itself would represent a serious impediment to the course of justice", she said.

The judges also rejected Robison's evidence that he had made checks in the court over reporting restrictions as "not credible".

They found that he "quite deliberately" reported on the case, which he had told his viewers was the subject of a reporting restriction.

Dame Victoria said Robinson's right to freedom of expression "could not justify an interference with fair trial rights".

A provisional date of 11 July has been given for Robinson's sentencing hearing.

The maximum sentence for contempt of court is two years in prison, but it can also be punished with an unlimited fine.