A teacher who suggested that a parent stick a pair of pliers "up his arse" during a row in a school reception, was found guilty of unacceptable professional conduct at the General Teaching Council for England this week.
Lee Warren, an art teacher, made the comment when he was confronted by a parent who was annoyed that his daughter's mobile phone had been confiscated because she was using it during a lesson.
Mr Warren, then employed at the James Hornsby High School in Basildon, Essex, had taken the phone to reception to be kept there until the end of the day.
But the pupil borrowed a friend's mobile to call her father to complain. He came to the school, retrieved the phone and gave it back to his daughter. She then used it to make further calls in front of Mr Warren.
At the end of the day, Mr Warren had volunteered to carry out repairs to a school toilet and was carrying a pair of pliers.
He received a message telling him that the girl's father was in reception and wanted to talk to him. The pair became involved in a "heated" row, where they were shouting at each other, a ruling by the GTC said.
"The committee accepts the evidence of Parent A, which was not challenged, that Mr Warren said words to the effect 'you can stick these pliers up your arse' and Parent A responded with words to the effect 'go on, have a go'," the ruling said.
The argument, which took place in November 2006, continued in the reception and staffroom areas.
The committee accepted that the parent instigated the argument, but criticised Mr Warren for allowing it to escalate.
In two separate incidents, the committee also found that Mr Warren called one pupil a "retard" and said to another that "he should have a brick dropped on his head". (CHK)
A further claim that he swore at a pupil and said he would "knock her out" was not upheld by the committee.
Mr Warren, who left James Hornsby High School soon after the incidents, was found guilty of unacceptable professional conduct.
The committee said that the school could have given him more support in dealing with the poor behaviour of certain pupils. The confrontation with the parent could also have been avoided if there had been more support, the ruling said.
Mr Warren was told he had to attend a training course on behaviour management and challenging pupils before he is allowed to teach again.