Fortnum & Mason claims protesters' sit-in cost £100,000

The carnivalesque chaos of the demonstration that took over Fortnum & Mason earlier this year was relived yesterday as the first 10 protesters appeared in court, charged with aggravated trespass.

Whistles, bagpipes, vuvuzelas and loudspeakers were blared while members of the activist group UK Uncut played beachball and pushed one another around the luxury London store in shopping trolleys on 26 March, Westminster magistrates' court heard.

District judge Michael Snow heard that staff and police officers could only watch as the shop was occupied by up to 300 demonstrators, who had broken away from the TUC rally against government spending cuts. CCTV footage, as well as film taken by some of the protesters, was shown, identifying all 10 of the defendants inside the store.

They were arrested that evening after being held within a police cordon upon leaving the shop, and are accused of intimidating staff and customers in such a way that they could not go about their ordinary business. The charges have been criticised as draconian and unfair by politicians and civil rights groups. The protesters' defence is likely to rest on allegations that police tricked them and carried out mass arrests as part of a "political policing" agenda.

Fortnum & Mason claim the action caused a loss of trade valued at between £54,000 and £68,000, in addition to repair and cleaning costs of £30,000 and a £4,000 bill for stolen or damaged goods.

The court watched a number of clips of one of the accused, Adam Ramsay, addressing an impromptu forum in the store's atrium to decide whether they should leave or stay longer. After a vote using "jazz hands" – a gesture whereby people comically shake their hands in the air – the group decided to remain in the shop for another hour, leaving at about 6.30pm having entered at 4pm. Mr Ramsay, along with the other defendants, has entered a plea of not guilty to the charges.

The store's facilities manager, Robert Mills, said the day had begun well, with a fun atmosphere among the crowds and some TUC demonstrators even downing their placards to shop in the store. But come mid-afternoon, he said he began to fear for the shop as he watched the mood "degenerate", he said, becoming "sinister and aggressive".

Despite having increased staff and security numbers by 20 per cent to deal with the any potential trouble, Mr Mills described how the store was overwhelmed by the "incursion". Adding that it all happened "like lightning" and that within two minutes the shop had been reduced to "absolute chaos", he said he quickly requested police back-up as soon as possible.

He recalled hearing a Champagne cork being popped – leading to a chant of "You can stick your royal wedding up your arse", as the bottle was from the Highgrove estate owned by Prince Charles.

The trial could last up to 15 days, and precedes two further trials of 10 more demonstrators each. Another 115 protesters initially faced charges that were later dropped.