Furious former students and parents held a noisy demonstration outside a Watford school this week to demand the reinstatement of a popular science teacher who was suspended after allegedly pushing a teenage student.

Martin Elvin, who has more than 15 years teaching experience, has been unable to return to work at Westfield Community Technology College since the incident which happened in June last year.

Despite being off for nearly eight months, the NASUWT union rep has not yet attended a disciplinary hearing.

Hertfordshire County Council – responsible for handling complaints in the first instance – says it cannot confirm or deny any details of the case and the school has refused to comment. Sources close to the case say the county council handed the matter back to the school in September, saying it could be dealt with internally.

On Wednesday, more than a dozen placard-wielding protesters gathered in a cold Croxley View, in a move designed to coincide with a visit by Ofsted inspectors.

Inside, students waved from windows and fire alarms sounded. It is not clear, however, whether the latter occurrence was related to the protest.

Protester and former pupil Chris Mundy is one of more than 500 people to sign up to a Facebook group in support of the teacher.

He said: “What is happening to Mr Elvin is totally wrong. He was the best teacher I ever had and made a huge difference to my life. A lot of people would agree with that.

“He is accused of pushing an unruly boy into a door when he was escorting him to a classroom but I can’t believe he would have done that on purpose.

“He is a teacher who really cares about his pupils. He helps them with college applications and job interviews. The school should be on its hands and knees begging for him to come back rather than forcing out the best teacher it has.”

Current students were not allowed to attend the demonstration but several vehicles full of teenagers – said to be sixth-formers – cheered and tooted horns in support.

Former pupil Dave Edwards, 28, added: “He was exceptional. He helped so many pupils overcome their problems, not just with science. It was him who pushed me in the right direction. It was him who helped with my college application and him who persuaded me to take education seriously. I now work as a linguist for a big company and a lot of that is because of Mr Elvin.”

Luke Edwards, 22, described him simply as “a legend.”

Although Mr Elvin is forbidden from speaking about the case, his family released a statement on Wednesday night.

It expressed “regret” for the disruption caused to the Ofsted inspection but thanked protesters for their support.

“We have also been moved to tears by the wonderful comments and messages which have flowed in today, this week and over the past months.

“Now it’s important that Westfield is back to normal on Thursday [yesterday] morning. Work with your teachers, it’s about your learning and education. It’s what Mr Elvin would want.”

The General Teaching Council (GTC), which rules on most serious complaints against teachers, said it has not been informed of any case against Mr Elvin.

It is understood, however, that he will attend a disciplinary hearing with school governors at the end of the month.