Police: We can't stop people flying Hezbollah flags on London march

“It is the words or actions of the person holding the flag that can cause incitement.”

She adds that, under the Humans Rights Act, “being a member or supporter of the wider non-proscribed organisation is lawful” so long as the British government has not proscribed the whole of Hezbollah.

Reacting to the letter, Ms Ellman said: “The Metropolitan Police have confirmed that they cannot prevent the flying of the Hezbollah flag on Al-Quds Day due to the policy of this government.

“We must remove this false and ludicrous distinction between Hezbollah’s political and military wings from UK law, and I would urge the new home secretary to take this action immediately.

"If we see the machine-gun adorned flag of an antisemitic terror group on London’s streets again this June it will be due to the inaction of the government – they must act now.”

At last year’s Al Quds Day march, the JC revealed, how  Nazim Hussein Ali , an Islamic Human Rights Commission speaker, linked the Grenfell Tower tragedy to “Zionists” and calling for Israel’s annihilation at this year’s Al Quds Day march.

Following complaints about Mr Ali’s conduct – and the open display of Hezbollah flags – the Metropolitan Police confirmed it was investigating allegations of antisemitic comments made during the protest by Mr Ali.

But in December the Crown Prosecution Service had he would not face criminal prosecution.