Teachers have been abused and threatened online by supporters of Tommy Robinson after he criticised a school on Facebook.
The former English Defence League (EDL) leader said Birchgrove Comprehensive School in Swansea had a head teacher "displaying fascist bullying".
He claimed a pupil was criticised for including him as a person he admired in an anti-bullying project.
Swansea Council leader Rob Stewart said events had been deliberately distorted.
A presentation ceremony due to be held at the school on Thursday was postponed and the school's social media accounts have been suspended.
Mr Robinson - whose real name is Stephen Yaxley-Lennon - wrote on Facebook that he had been told a pupil at the school had written on a board that they respected him "because he stands up for the British public".
He claimed the school took action to try to identify the pupil who wrote the praise.
Writing on Facebook, Mr Robinson added: "This just underlines how our education system has been infiltrated by far-left fascists. Surely pupils are allowed to have free thought and opinion?"
Swansea Council leader Rob Stewart said: "I fully support our teachers at Birchgrove Comprehensive School and I find it abhorrent that the events in the school have been badly and deliberately distorted.
"It is unacceptable for teachers to be the target of abuse by far right supporters on social media."
In May, Mr Robinson, 35, was jailed for 13 months for contempt of court, which sparked a series of #freeTommy protests.
His conviction was later quashed over procedural concerns and the case has now been referred to the attorney general.