The prime minister recently declared that Britain “fiercely” protects free speech. Fine words – but they will ring hollow to Hamit Coskun, who was convicted for burning a Quran during a political protest.

The National Secular Society is backing the appeal of Coskun’s conviction. Not because we endorse his actions – we don’t – but because the principle at stake could not be more important. Free expression does not exist to protect polite or popular opinions. It exists to protect those that anger, unsettle, or offend. And it is precisely when speech offends that our commitment to that principle is truly tested.

Coskun’s protest was not directed at any individual, but at the Erdogan regime, its erosion of secularism, and the rising tide of Islamism in his native Turkey. As an act of symbolic, non-violent dissent, he set fire to a copy of the Quran outside the Turkish consulate.

Despite the peaceful nature of his demonstration, he was convicted under the Public Order Act for “disorderly behaviour” in the presence of someone “likely to be caused harassment, alarm, or distress”. The judge further ruled that his protest was “religiously aggravated”, meaning it was motivated in whole or in part by hostility towards Muslim people.

It bears repeating: Coskun threatened no one, harmed no one, and committed no act of violence. The violence that day was directed at him. Offended by the sight of a man burning a Quran, Moussa Kadri threatened to kill Coskun, left to fetch a knife, returned armed, and attacked him. While lying on the ground, he was then apparently attacked by a passing delivery driver.

For that assault – an actual, premeditated act of violence – Kadri received a suspended 20-week sentence and walked free from court. The other assailant was never caught.

Coskun’s conviction sets the bar too low in terms of when the state can legitimately interfere with someone’s right to free expression, as protected by article 10 of the Human Rights Act. According to Lord Justice Sir Stephen Sedley in a 1999 ruling:

“Free speech includes not only the inoffensive but the irritating, the contentious, the eccentric, the heretical, the unwelcome and the provocative provided it does not tend to provoke violence. Freedom only to speak inoffensively is not worth having”.

Yet the Coskun ruling suggests that doing anything within the hearing or sight of a person likely to be caused “harassment, alarm or distress” can be enough to criminalise expression. This gives disproportionate power to offended parties. Even more concerning, people willing to threaten or use violence are effectively being allowed to define the boundaries of free expression. The judge found Coskun’s protest to be “disorderly” because it provoked “serious public disorder” – that is, because he was attacked by two separate individuals. In other words, the violent reactions of others were treated not as evidence of their intolerance, but as proof of his guilt. Plainly, this is victim-blaming.

We appear to be becoming a society where causing offence is treated as a crime, and where “harassment” and “alarm” are invoked to police speech. The result is a creeping ‘heckler’s veto’ – where those who are “alarmed” or willing to threaten or commit violence get to decide what can and cannot be said.

This veto is being wielded most aggressively in relation to Islam. We’ve seen it time and again: cartoonists butchered in Paris for drawing Muhammad; Salman Rushdie forced into hiding – and later stabbed – for writing a novel; a teacher in Batley living under police protection for showing a class a cartoon. The list goes on.

If we respond to this intimidation by punishing the speaker rather than defending their right to speak, we strengthen the heckler’s veto – and guarantee we will see a lot more of it. People will think twice before criticising religion, publishing satire, or challenging powerful ideas. The space for dissent will shrink – for all of us.

None of this is about endorsing Quran burning or any form of book-burning. It is about defending the principle that people deserve protection from real harm, but ideas do not – even when those Ideas are offensive or hurtful. It’s worth remembering that Coskun was originally charged with harassing the “institution of Islam.” Prosecutors backtracked and substituted the charge after the NSS exposed how extraordinary and mistaken the original charge was – but their intent was clear. Once we start shielding beliefs from criticism or insult, we place them beyond challenge, weakening free expression and undermining the foundations of liberal democracy.

Thanks to our campaigning, Britain abolished its blasphemy laws more than a decade ago. We must not allow them to return by stealth, under the guise of public order laws against “harassment” or “religious hatred.”

Well-meaning attempts to limit speech in the name of social harmony often have the opposite effect. Free expression is not a threat to a cohesive, tolerant liberal democracy; it is one of its essential preconditions. And the right to offend is not a regrettable byproduct of free speech, it’s the very point of it.

If we are serious about “fiercely” defending that right, we must set the bar for restricting expression far higher than the conviction of Hamit Coskun suggests.