But town hall staff insist they had told British National Party supporter John Rowe that the venue’s public gallery had been closed for a full council meeting in February, 2008, Burnley Crown Court heard.
Councillors and mayor Coun Ida Carmichael, along with staff and the public, were forced to evacuate the building just after 7pm.
Police arrested Rowe, who was found inside the town hall complex and he was later convicted by Burnley magistrates of causing criminal damage. He later lodged an appeal against the ruling.
Problems began when Rowe, 54, of Tennis Street, Burnley, arrived to witness the council meeting, the crown court was told.
Because of previous altercations with officials, Rowe had been told that he must give 48 hours notice, in writing or by telephone, if he wanted to turn up for meetings.
Head porter David Bristow said Rowe, who attended the meeting with a pushbike, was told he should not sign the visitors’ book as he was barred from the proceedings.
Mr Bristow said: “He was obviously upset and said it was ‘bloody ridiculous’ that he was not allowed in, and that he had every right to be in there as a member of the public and a council tax payer.”
Giving evidence later, receptionist Diane Whittle said she told Rowe that the gallery was closed for the meeting.
Mercedes Jabbari, representing the respondents, said Rowe was seen walking along a corridor towards the gallery when the alarm sounded.
Martin Hackett, defending, said Rowe’s case was that, on finding the door to the gallery locked, he genuinely believed people on the landing would be trapped in the event of a fire.
Rowe said, in the witness box: “It appeared to me that if I was locked out then other people would be locked in.”
Earlier Mr Bristow had said that the fire door could only be opened from the inside.
Judge Andrew Woolman, sitting with magistrates, dismissed Rowe’s appeal.