Hamas has vowed to contest its proscription as a terror group. The Palestinian militant group instructed British lawyers to challenge the designation, arguing it was a “political” decision by former Home Secretary Dame Priti Patel.

And Riverway Law, an immigration firm based in Streatham, south London, has confirmed it has begun legal proceedings against the Home Office. The firm said on Wednesday: “Today, Fahad Ansari of Riverway Law launches an important legal application to Yvette Cooper MP to end the ban on the organisation Harakat al-Muqawwamah al-Islamiyyah (Hamas).”

But Shadow Home Secretary Chris Philp blasted: “Hamas is a despicable terrorist organisation who deliberately organised and carried out mass murder, rape and kidnap of innocent children, women and men on October 7, 2023.

“They are responsible for many terrorist atrocities and brutally oppressing the people of Gaza. They should be proscribed, and this legal claim should be dismissed.

“The fact that lawyers are seriously arguing our weak human rights laws could be twisted to protect murderous terrorists shows why these laws are no longer fit for purpose.

“Human rights laws should protect our citizens – not foreign criminals and possibly even terrorists.”

Announcing the action, Riverway Law claimed: “The right to resist occupation, apartheid and genocide is firmly entrenched in international law.

“Like them or loathe them, Hamas is the manifestation of the Palestinian resistance.

“By banning it, Britain is effectively denying Palestinians the right to defend themselves against extermination."

In 2021, then-home secretary Ms Patel argued it was not possible to distinguish between Hamas’s political and military wings. She called Hamas “fundamentally and rabidly antisemitic”, adding the proscription was required to protect the Jewish community.

Hamas said in its legal submission: “Hamas does not deny that its actions fall within the wide definition of ‘terrorism’ under the Terrorism Act 2000. Instead, it notes that the definition also covers all groups and organisations around the world that use violence to achieve political objectives, including the Israeli armed forces, the Ukrainian army and, indeed, the British armed forces.

“Of course, not all such groups are proscribed as ultimately that is a question of discretion for the Secretary of State ... Transition to a political process is hindered by the terrorism label, as talking with terrorists is a taboo.”