British police said they had banned a pro-Iranian march due to take place in London on Sunday, citing the possibility of "extreme tensions" with counter-protesters and the risk posed by Tehran during the conflict in the Middle East.

The Al Quds march in central London is organised annually by the Islamic Human Rights Commission, which the police said was supportive of the Iranian regime.

The threshold to ban a protest is high in Britain, with the police saying this was the first time the power had been invoked in 14 years, but the risks of public disorder were "so severe" it was right to block it. The ban also applies to any counter-protest marches.

The Islamic Human Rights Commission has previously said on X that the march was being held in support of Palestinian liberation.

Police said that previous Al Quds marches have resulted in arrests for supporting terrorist organisations and anti-Semitic hate crimes, and said that even with the ban in place they were facing a "challenging, potentially violent weekend".

"We have taken into consideration the likely impact on protests of the volatile situation in the Middle East, with the Iranian regime attacking British allies and military bases overseas," the police statement published late on Tuesday said.

"We must also consider that the security services have been publicly clear about the threats we are facing on UK soil from the Iranian regime."

British police have faced heavy scrutiny of their handling of regular, large pro-Palestinian protests in London since the October 7, 2023 attacks by Hamas on Israel, with supporters and opponents at odds over the right of free speech, the support shown for a proscribed group and the impact on the Jewish community.

Last week, British police arrested four men on suspicion of helping Iran's intelligence services carry out surveillance of people and locations linked to the Jewish community in London.

Should the Islamic Human Rights Commission go ahead with a static assembly, which there is no law to ban, police said it would be placed under strict conditions.