HOME SECRETARY Yvette Cooper’s decision to ban Palestine Action as a terrorist organisation has the hallmarks of a “blatant abuse of power” and an “unlawful interference” with freedom of expression, the High Court heard yesterday.

Lawyers for the activist group’s co-founder Huda Ammori asked a judge to allow a full legal challenge to the decision, arguing that it was “so extreme as to render the UK an international outlier.”

Ms Cooper announced that the group would be proscribed under anti-terror laws after it claimed responsibiity for damaging two Voyager planes at RAF Brize Norton on June 20.

On July 4, Ms Ammori failed in a High Court bid to block the ban temporarily, with the Court of Appeal dismissing a challenge to the Home Secretary’s decision less than two hours before the proscription came into force on July 5.

Yesterday, Raza Husain KC said: “We say the proscription of Palestine Action is repugnant to the tradition of the common law and contrary to the ECHR [European Convention on Human Rights].

“The decision to proscribe Palestine Action had the hallmarks of an authoritarian and blatant abuse of power.

“The consequences are not just limited to arrest,” he added, telling the court that there was “rampant uncertainty” following the imposition of the ban.

Blinne Ni Ghralaigh KC, also for Ms Ammori, said: “The impacts [of proscription] have already been significant.

“Dozens and dozens of people have been arrested for protesting, [in] seated and mostly silent protest.”

More than 100 people were arrested across the country at demonstrations last weekend against the proscription, which makes membership of or support for the direct action group a criminal offence punishable by up to 14 years in prison.

Saturday’s arrests brought the total number of people arrested since the ban came into force to more than 200.

Sir James Eadie KC, representing the Home Office, said that an “exceptional case” would be needed for Palestine Action to be permitted to challenge the Home Secretary’s decision at the High Court, rather than through the Proscribed Organisations Appeal Commission, a specialist tribunal.

Justice Chamberlain will hand down his judgement at a hearing on July 30.