The Al Quds Day march this weekend has been banned by the government, with the Home Secretary warning it risks “serious public disorder. Despite that, pro-Iran-Palestine activists are allowed to stage a ‘stationary’ protest and, with counter demonstrators expected, Londoners can look forward to yet another weekend of potential disorder. But other than the obvious implications for public safety and policing costs, why should British taxpayers care about this march?

To understand that, we must look at the history of Al Quds Day. The event was established after the 1979 Islamic Revolution in Iran and is officially presented as a day of solidarity with Palestinians. But for those who created it, solidarity means something far more radical: the destruction of Israel.

You might think such a cult would be operating in the shadows, yet having been allowed to protest tomorrow, Londoners will face images of the late Ayatollah Khamenei, the man whose brutal regime killed more than 30,000 of his own people in less than two months.

“Al Quds” is the Arabic name for Jerusalem. Iran’s first Supreme Leader, Khomeini declared that Muslims around the world must regard Quds Day as “the day of all Muslims — indeed, of all the oppressed “ to “stand firm against the arrogant powers and global oppressors, and not rest until the oppressed are freed from the tyranny of the imperialists”.

Sound familiar? It is the ideological blueprint for “Globalise the Intifada”. Khomeini himself made this clear when he said: “Al Quds isn’t only about Palestine. It is the day of Islam and Islamic rule.”

The fact that organisers have had the power to hold such a march in London should alarm us all. Yet Al Quds Day is only the tip of the iceberg. According to a report by the government’s former independent advisor on terror, Lord Walney, the Islamic Republic has exploited Britain’s charity system to advance its soft-power goals. Astonishingly, there is even an office in London representing the Supreme Leader of Iran.

What message does this send to our allies in the Middle East? That we allow supporters of the government that bombed your oil reserves and civilian buildings to protest here? What message does it send to the Iranian community – that we allow the government which destroyed your country to operate here and make you feel unsafe again?

What does it mean for that Iranian protester in London who discovered her brother had died only when she saw his picture on a billboard? And what about our Jewish community? That a day whose goal is the destruction of Israel can go ahead and broadcast its message of hate?

The problem is consecutive governments have been tolerant of Islamist extremism. Dangerous groups like the Muslim Brotherhood and IRGC are influencing our most important pillars of civil society. This is why the Al Quds march should be banned. Democracies should not allow their enemies to exploit democratic freedoms in order to undermine them. Tolerance cannot be a one-way street. When it is, the intolerant weaponise the liberties of a free society against the society itself.

I remember when I lived in Iran. Al Quds Day was the day you saw members of the Basij militia and the Islamic Revolutionary Guard Corps — the same forces that killed my compatriots — marching through the streets chanting “Death to Israel,” “Death to England,” and “Death to the Great Satan,” meaning the United States. Frankly, I do not want to see those who helped destroy my country bringing that same ideology to Britain. Nor should the government or public.