We do not have the right to disrupt one another’s lawful activities, and nor should we have. If, for example, I have paid to watch a professional snooker match, you do not have the right to disrupt it by sitting on the snooker table and pouring orange powder all over yourself. Or if I am seeking to watch a film, screened in a cinema or lecture theatre, you do not have the right to stop me by blockading the entrances to the auditorium.

You would not be exercising your right to free speech by protesting in such a way. It is not your speech which disrupts my enjoyment of the snooker or my ability to watch the film. It is your actions that would stop me, not your speech.

Regular readers of this column will know that I am a passionate advocate for and defender of free speech. But the right to freedom of speech is meaningful only if we can distinguish speech from action. There is no right freely to act howsoever you wish, just because you have a message you want folk to notice.

You might claim, in the alternative, that you are exercising your right to protest in such a case. Again, you would be mistaken. European human rights law knows no such thing as a right to protest. Instead, there is a right to freedom of peaceful assembly—it’s in Article 11 of the European Convention on Human Rights. This is a much more restricted right than the right to free speech. The latter is not qualified, for example, by the need to show that speech is peaceful.

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That the right to assemble is restricted to peaceful assembly means, rather obviously, that there is no right to riot. Violent public disorder is never accommodated within the right to freedom of assembly –rioting is now, as it always has been, unlawful. Riot is a crime with a long history, stretching back centuries. But to what extent does the right to freedom of peaceful assembly extend to and protect public protest which, whilst not violent as such, is nonetheless deliberately designed to disrupt the lawful activities of others?

Sitting on a snooker table with a pot of orange powder is not violent, but it is clearly disruptive – and is wilfully designed to be disruptive. Likewise, blockading the entrances to a theatre to prevent members of the public from getting in to watch a film. Such a sit-in is not violent, but it is manifestly disruptive. It is a forceful use of human, physical presence to coerce others.

The European Convention on Human Rights (which forms the basis of our human rights laws in Britain) is clear that the rights and freedoms it enshrines may not be used to prevent or obstruct the exercise of other people’s rights and freedoms. This is what prohibits racist speech, for example. I cannot use my right to freedom of speech to deny your humanity or your dignity on the basis (for example) of your race – racist speech is hate speech and, as such, it is not protected by the law. There is no right to be racist.

The same holds for those who wish to act in such a way as to disrupt the lawful activities of others (there is nothing illegal about playing snooker). And, again, the same holds too for those who wish to prevent others from watching a film. There is no right to be intolerant.

These are easy cases. Or, at least, they ought to be. But what if we change the facts slightly? What if a small group wishes to protest (peacefully) in the near vicinity of a large crowd who might be very annoyed at that protest. Can the police intervene on the protesters to ensure there is no public disorder?

This is close to what happened in Westminster on the day of the King’s Coronation. A small group of republicans wanted to protest against the monarchy at a time and in a place where tens of thousands of people were gathered to watch and to take part in the coronation celebrations. The police prevented the protest, by arresting the would-be protesters and detaining them in police custody. Where they right to do so?

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The police had every right to act as they did if they intervened to prevent a breach of the peace. No crime needs to be committed before the police may exercise preventive powers to avoid a breach of the peace. But two conditions must be met for such police action to be lawful. First, officers must believe there will be an imminent breach of the peace and, secondly, this belief must be reasonable. If the police act too soon, or exercise their preventive powers disproportionately, they will be acting unlawfully.

The facts of what happened at the Coronation would appear to indicate that the police suspected a number of the protesters were seeking to act disruptively by, for example, locking themselves on to obstructions which could have interfered with the Coronation procession. Even if the police turn out to be wrong about that, arrests would still be lawful as long as the officers at the scene reasonably suspected an offence may be about to be committed. The police do not have to wait for an offence actually to be committed before making an arrest. Far better to prevent crime than to wait for the harm to be done and only then to act in response.

Given the range of disruptive activity protesters of various stripes have engaged in of late in Britain, it is understandable that the police would be nervous and hyper-vigilant that such tactics should under no circumstances be permitted to disrupt a spectacle as important as the coronation. There are, no doubt, lessons for the police to learn – but so, too, are there lessons for protesters. There is no right to seek to disrupt the lawful activities of others. If public protest were carried out in compliance with this basic principle, and not in violation of it, we would all be a great deal better off, police and protesters alike.

Adam Tomkins is the John Millar Professor of Public Law at the University of Glasgow School of Law. He was a Conservative MSP for the Glasgow region from 2016 to 2021.