THE head of England's leading republican movement is set to sue Met chief Sir Mark Rowley in what has been described as a first test case of new anti-protest legislation.

Graham Smith was arrested at an anti-monarchy protest in London on Saturday, May 6 along with seven campaigners for the group Republic, which had liaised with the Met to organise a coronation day protest in Trafalgar Square.

They were arrested on suspicion of going equipped to lock-on, but were released 16 hours later without charge.

Following the arrests, Rowley insisted police had “serious and reliable intelligence” that protesters planned to disrupt the coronation by using rape alarms or loud hailers during the coronation procession.

READ MORE: Coronation: Who is Graham Smith? The Republic leader arrested

Later, the Met expressed regret for arresting the group and said it was "not clear at the time" to the arresting officers that "at least one of the group stopped had been engaging with police" about holding a lawful protest prior to the Coronation.

"We regret that those six people arrested were unable to join the wider group of protesters in Trafalgar Square and elsewhere on the procession route"

READ MORE: Metropolitan Police 'regrets' arrest of Republic protesters

Smith’s lawyers have said the case will be the first time that a court has had the chance to consider the “correct approach” when it comes to the Public Order Act – which gives police in England sweeping powers to crack down on peaceful protest.

Smith said: “The important thing is that we need answers as to where the law stands on the right to protest and there is a matter of natural justice for those of use involved. I for one would certainly like to hear a full-throated apology from the Metropolitan police.”

The case lodged by Graham Smith

It is claimed by Smith’s lawyers that officers who arrested him did not have reasonable grounds to suspect an offence would be committed  “because of his extensive communication and cooperation with the defendant’s officers in respect of the protest”.

The team further claimed there was no need for an arrest as police could have employed alternative means “of avoiding any purported risk of disruption”, such as seizing the banners in his possession.

In a 39-page statement of facts, it states: “[Smith] informed the defendant’s officers of the details of where and when the protest would be carried out, how many people would attend the protest, and that Republic would be bringing a large number of placards for use by attendees.

READ MORE: MPs to probe coronation protest policing after Republic arrests

“The defendant’s officers did not raise any objection to this planned protest and assured him that the defendant would facilitate this planned protest in accordance with articles 10 and 11 of the European convention on human rights.

“On 6 May 2023, the claimant attended the site of his planned protest with a number of colleagues from Republic. The defendant’s officers did not facilitate the protest as the claimant had been assured they would. Instead, they arrested the claimant and held him in detention for over 14 hours.”

What is the Met saying?

In a formal response, the Met has called for the High Court to reject Smith’s request for a judicial review.

They argue the threshold for an arrest is a “low one” and defend the arresting officer by saying he had reasonable grounds to arrest Smith.

A Scotland Yard spokesperson said: “We can confirm that a judicial claim has been issued. It would be inappropriate to comment on ongoing proceedings.”