A parent-teacher association for an Anglican primary school in Kent has apologised after members taking part in a well-known bonfire night celebration wore blackface makeup, among them a local Conservative councillor.

Hever Church of England school said a small number of people connected to the PTA had worn the makeup when they marched alongside the school’s float at the celebrations in Edenbridge on Saturday.

The town stages a large procession of carnival floats through the centre to the site of the bonfire where an effigy is burned. This year the local bonfire society chose Boris Johnson.

The school’s float had a Caribbean theme. Photographs of the event sent to the Guardian show Trevor Bryant, a Conservative member of Edenbridge council, wearing a frilly shirt and hat, with blackface makeup.

Bryant confirmed he had worn the makeup, but said he had no further comment.

It echoes a longstanding row over the similar if better-known bonfire night celebrations in Lewes, East Sussex, where some participants traditionally wore Zulu-type outfits, and blacked up their faces.

Joanna Stratton, the headteacher of Hever school, said there had been “an error of judgment” by a small number of people from the PTA who took part in the celebration.

“The school was not aware of the content or format of the PTA participation, and only became aware of it after the event,” she said. “The school is proud of its multicultural staff and pupils and does not tolerate any racism or bullying.

“I have spoken to the PTA and they would like to apologise unreservedly for any offence caused. There was no intention to hurt anyone’s feelings and any upset caused is completely contrary to what they hoped to bring to Bonfire night. I will be speaking to the PTA further to ensure there is no repeat of this.

“We are very proud to be a multicultural school with ‘respect, love and wisdom’ as our motto.”