Police 'suppressed anti-Royalism during Royal Wedding'
The Metropolitan Police effectively "suppressed anti-monarchist sentiment" during the Royal Wedding in London last year, the High Court has been told.
Some 20 individuals arrested or subjected to searches before or on the wedding day are arguing in court that police operated an unlawful policy.
They claim it violated the fundamental democratic right to protest.
Activists say the case has major implications for the policing of the Diamond Jubilee and the Olympics.
However, Lord Justice Richards suggested the court's ruling was likely to come too late to affect policing of the Jubilee.
The applicants say they were pre-emptively arrested ahead of the Royal Wedding, on 29 April last year.
Police officers said they suspected them of being about to commit breaches of the peace.
Scotland Yard, which has not commented on the case, believed paint bombs may have been in the area of the raid - but none was found.
Theodora Middleton and Dafydd Lewis allege that police misled a judge in order to obtain a search warrant.
'Most important right'
Karon Monaghan QC, appearing for 15 of those arrested, said the signal for their release from custody was "the balcony kiss" of the royal couple.
She claimed the Met "operated a policy of equating intention to protest, whether perceived or actual, with intention to cause unlawful disruption".
Ms Monaghan said the issues at stake were "the most important of constitutional rights, namely the rights to free expression and to protest, both of which are elemental to a properly functioning democracy".
She argued police "adopted an impermissibly low threshold of tolerance for public protest, resulting in the unlawful arrests of those who were viewed by officers as being likely to express anti-monarchist views".
BBC legal correspondent Clive Coleman says with the Queen's Diamond Jubilee one week away and the Olympics this summer, the case could set the tone for the balance between pre-emptive policing and the protection of civil liberties, in the run-up to major national events.
The case continues.