Music by The Clash was used to deprive last year’s climate campers of sleep, a new report by the Lib Dems has claimed.

Playing loud music was just one of the tactics used by officers to combat the environmental protesters in Hoo last August, according to the report, which has been published by David Howarth, Liberal Democrat Shadow Justice Secretary, with the climate camp legal team.

The document is based on eyewitness accounts and is supported by video footage.

It claims the police used a number of ways:

to harass the protesters, including:

• Stop-and-search powers

• sleep deprivation tactics [such as broadcasting the Clash’s I Fought The Law in the early hours of the morning]

• Seizure of hundreds of personal items including soap, clown costumes and board games.

The document states that officers pressurised campers to give their personal details when they exercised their right not to, threatened individuals with foreign accents with arrest for immigration offences and obstructed legal observers, including threatening arrest for conspiracy.

The report also claim that officers aggressively threatened the peaceful procession on the day of action, which involved children, the elderly and people with disabilities.

Liberal Dem leader Nick Clegg said: “The harassment of thousands of protesters who were peacefully campaigning against new dirty coal in Kingsnorth highlights just how shallow Ed Miliband’s call for a mass movement against climate change actually is.

“The longer the government fails to act to safeguard the environment, the more protests and calls for action there will be.

“It would be inexcusable if suppression of protests became a substitute for dealing with the root causes of climate change.”

David Howarth said: “The evidence contained in this report is deeply disturbing, the police tactics employed at Kingsnorth were out of all proportion to any threat posed by the protesters and were an affront to civil liberties.

“It is impossible to square what happened - an extraordinarily expensive and repressive police operation - with government descriptions of it at the time as ‘proportionate’.

“The police seem to have crossed an important line between preventing crime and preventing protest itself. To equate people who want to protest against government policies on climate change with violent extremists is absurd.

“There must be an immediate inquiry into the policing of environmental protest and into the politicisation of the policing of protest generally.”

Kent Police statement

The policing operation around Climate Camp was large, complex, arranged at short notice and without the co-operation of protest organisers. It was an illegal mass trespass without the consent of the landowner. The stated intention from the outset was to break into the power station, putting lives and the power supply to 300,000 residents at risk. This meant we had to plan and carry out one of the biggest police operations seen in the county for more than 25 years.

The police operation itself was very successful in preventing such criminality and harm while at the same time, enabling a protest around an issue of genuine public concern to go ahead. Kent Police fully accept the right to protest as part of our democracy.

While the majority of protestors at Climate Camp were law abiding, it was clear from the first day of the camp setting up that a number of people were intent on causing trouble, and they made public their intention to break into the power station by any means.

By seizing items which could have been used to commit a crime we were able to ensure that criminal acts were not carried out and, more importantly, that no one was injured by some of the items which potentially could have been used to harm others. These included knives, spears and grappling hooks. There could be no innocent explanation for people carrying these items.

We hope that anyone who attends a similar event in future accepts their responsibility to do so lawfully and in a legal manner.

The majority of the comments around the police operation from the people of Kent were wholly supportive of our actions.

As with any major police operation, we always review our procedures and protocols. Like any forward thinking police force we are always keen to learn and develop the way we protect the people of Kent.