Gerald Maughan, 37, admitted turning up to the council offices on Thursday afternoon before laying into shatterproof glass doors with the heavy weapon.

Council staff watched in horror as Maughan caused hundreds of pounds of damage to the front of the Boulevard office in the broad daylight attack.

But Crawley Magistrates' Court heard on Monday that the 37-year-old didn't put up a fight when town hall attendants stepped in to restrain him before calling the cops.

A council spokesman said: "He turned up at the town hall, broke the windows, didn't make any struggle, was detained and then arrested.

We have had contact with him for several years but the last time he contacted us was in August 2007 so this visit was completely out of the blue and a complete surprise. I don't know what his motive was." Reception staff and town hall assistants said the hammer attack happened so fast they reacted instinctively.

The spokesman said: "They said the incident happened really quickly and was almost over before it started or for them to be shocked. They just did what they had been trained to do and went into automatic. "Once he was detained by members of staff he was very calm and didn't struggle at all."

It's thought the man had pitched up at the council before, claiming to be homeless, and had been offered temporary accommodation.

But the council spokesman said that he had no record of violent behaviour.

He added: "We have a list of people who act in certain ways so that our staff can be prepared, but I'm not aware that he was on it."

A police spokesman said: "Police attended the town hall after reports of a man causing damage with a mallet to the windows.

"The man was detained by staff at the town hall."

Gerald Maughan pleaded guilty to criminal damage in and was remanded in custody until sentencing at Mid Sussex Magistrates Court on July 21.