Some food for thought from inside Fortnum & Mason

The occupation of Fortnum & Mason, best known for providing picnic baskets to the Royal Family, was held in typical UK Uncut style. Followers were directed to the secret meeting place by groups brandishing green and red umbrellas at Oxford Circus. At 3.30pm, 400 anti-cuts protesters, including me, entered the Piccadilly department store for a demonstration punctuated by poetry readings and guitar playing.

Shelves stocked with jars of marmalade, silver platters and bottles of champagne were soon home to carefully crafted banners, such as "Closed by UK Uncut" and "Big Society Bail In: We Won't Pay for their Crisis". While I was checking incoming tweets from news channels documenting the escalating violence outside, UK Uncut members were busy holding a meeting around the three-storey spiral staircase. They decided all actions via consensus-decision making, whereby you can indicate approval of an action by a quick show of jazz hands.

This was the day of the TUC March for Alternatives. "UK Uncut really offers an alternative," said Anna Mason, 15, from Liverpool, as she showed me her home-made sign against tax evasion. "We are peaceful, making a point, and haven't broken anything." While groups such as Black Bloc were smashing windows on Oxford Street, UK Uncut members were reading books in groups on the floor and tucking into home-made sandwiches. Cate Howard, 47, a tourist from Boston, said she found it "all a little bemusing" before she was led away into the manager's office with the rest of the customers.

UK Uncut conducted itself with this peaceful etiquette throughout the three-hour occupation of Fortnum & Mason, a shop they said they had chosen because a related company allegedly avoided £40m in taxes.

Despite being detained in the store, Joan Higgins, 61, from Liverpool, described the protester's theatrical show as "the perfect accompaniment to my tea and scones". The exit was slightly less polite.

Police officers inside the building thanked protesters for their cooperation and promised that they could leave together without interrogation. Outside, however, riot police pushed those who exited into a small area where they were unlinked by force, photographed, arrested and led away. The protesters, who spent the night in police stations around London, believed they had been duped. Or communication between police inside and the force outside the shop had completely broken down. The riot police told me that protesters were being arrested for "aggravated trespassing" and that the customers unable to leave the shop were "scared half-to-death". A spokeswoman for Fortnum & Mason said: "The damage is minimal. We have cleared up after the disruption and are now helping our neighbours on Piccadilly do the same. The store is open for business as usual."