People who complained that they were beaten and unlawfully restrained by police during the G20 demonstrations have won a judicial review of the tactics used by officers during the event.

The announcement yesterday coincided with the publication of an HM Inspectorate of Constabulary (HMIC) report which warned that the police risked losing the public's sympathy and consent if they did not review the way public protests were policed.

The legal challenge was brought against the Metropolitan Police by three protesters.

Researcher Chris Abbott, student Hannah McClure and Josh Moos, a campaigner for Plane Stupid, claim they were kettled and violently treated by police during the protests in London's Bishopsgate in April this year.

They aim to prove that officers from Scotland Yard broke the law in their attempts to police the protest. Solicitor John Halford of Bindmans, who represents the three protesters, said a full judicial review hearing would be held in the Administrative Court next year. If they win, the trio could be awarded damages.

Mr Halford said: “The court's decision granting permission for judicial review in this litigation and the HMIC report highlight a fundamental problem with the policing in Britain.”

The report, Adapting to Protest: Nurturing the British Model of Policing, said that controversial tactics for tackling highly charged demonstrations could erode the public's traditional support for police.

It added that apparently unfair and aggressive moves may help officers keep order at protests but they risked damaging confidence in the police service.

It also criticised the variation between forces in tactics, training and equipment and stressed the need for a consistent approach.