Nearly 250 Tokyo high school teachers disciplined for refusing to sing the national anthem during school ceremonies have been forced to attend a “re-education” programme, accompanied by their headteachers.

Such programmes, ordered by the Tokyo board of education, are normally reserved for teachers who have sexually harassed schoolchildren or committed embezzlement, their lawyers said.

“The board is saying that what we did out of conscience was no different from sexually harassing children,” said Naoyuki Hoshino, a high-school teacher from the outskirts of Tokyo.

Following the Tokyo district court’s warning last month that the training sessions could infringe individuals’ freedom of thought - which is guaranteed by Japan’s constitution - the programme was cut to two hours, and in the end skirted around the subject of the national anthem or the flag itself.

Instead, the teachers - most of whom attended the programme this week - were given a lengthy reminder of civil servants’ duty to obey the board and the consequences of refusing to do so.

“We were warned that we would face a reduction in pension, a pay cut or possibly a dismissal,” said Eishun Nagai after attending the course. They will all now be placed under their headteachers’ surveillance for two months.

The court is still deliberating on whether the board’s initial directive making the anthem-singing compulsory was constitutional.

Nearly 200 teachers have filed complaints with their local authorities insisting that the disciplinary actions be withdrawn. The eight teachers who lost their jobs have sued the board and demanded reinstatement.

Mr Hoshino said he is determined to fight on.

“I’m past caring about what might happen to me because I’m so angry with the board,” he said, “I’ve been a teacher for 38 years but psychological freedom is fundamental to human beings. I have to fight on because Japan’s future is at stake.”