Explained: Former chief prosecutor on Parliament, protests and police

The abuse heaped on politicians and broadcasters outside the Houses of Parliament in recent weeks has brought the issue into sharp focus.

Here, former director of public prosecutions Lord Macdonald discusses events on College Green, and the challenges facing the police in responding to calls to intervene.

What sort of crimes could be being committed?

“It’s very important to protect the right to engage in robust political exchanges. That has to be protected and people have to be able to speak strongly and robustly – even very robustly.

“But if we have groups of men – and they are men – roaming around Parliament Square, surrounding politicians at very close quarters and shouting abuse, that is not political discourse, that is abuse.”

Where is the line crossed?

“If we have people standing there, across one side of the road, saying ‘We want Brexit’ or ‘no to Brexit’ or whatever, that’s fine. Even shouting ‘traitor’ at a politician, say from across the road, that’s by and large acceptable.

“But a group of men surrounding someone, following them, screaming in her face – that is not.

“She (Ms Soubry) was standing at the gate waiting to get in to Parliament, and this group of men were shouting, screaming at her, that she was a Nazi, they were right in her face.

“That is not an exercise of free speech – it’s a deliberate attempt to harass.”

What about the police response so far?

“I’m surprised the police have taken so long to intervene.

“I think Anna Soubry has been the victim of criminal conduct for weeks. As soon as it got to the stage they were surrounding her and shouting at her, that’s straightforward harassment. They have the intention to cause alarm and distress.”

Could those seen surrounding MPs in this manner say they have a right to get their point across in this manner?

“There is no defence for this. If they want to go up close and say ‘we don’t agree with you’, that’s one thing.

“But if they are saying the things they have been saying, inches from her face, it’s inappropriate.”

Police have said they will act ‘robustly’ – what should they be doing now?

“Police should be looking at evidence on video and arresting those responsible.

“If the police share my analysis that surrounding someone and going in their face and chanting abuse at them is a criminal offence, they should be picking them up and arresting them.”

What sort of criminal punishment could await those convicted in this case?

“This is at the lower end of the scale of violent behaviour, and so it is more likely a non-custodial sentence will be the result. But for repeated behaviour, I think a jail term is likely.

“The police are in a very difficult position – if they intervene, it’s controversial. If they don’t intervene, it’s controversial.

“We have to reserve people’s rights to express their views robustly. But this is not an expression of views – it’s abusive, threatening behaviour in circumstances where someone is likely to be left feeling harassed or abused.”

What does the current situation suggest?

“We seem to have arrived at a situation where a small group of men have taken it upon themselves to roam around Parliament Square threatening and intimidating politicians and journalists.

“They are not engaged in political discourse or the exercise of free speech, they are engaged in threatening behaviour and harassment and they have been doing this persistently for weeks.

“They are committing criminal offences in plain sight, unmolested by the police, and it is time for the law to intervene.”