Esmail Abdi, General Secretary of the Teachers Trade Association has had his six year jail sentence confirmed by the Tehran appeals court.
He was arrested last year as he was on his way to take part in the Education International congress in Ottawa. He was kept in solitary confinement for a month and interrogated for 15 hours a day according to reports.
Mr Abdi has been charged with 'gathering and colluding with intent to harm public order' and 'propaganda against the system.' In fact he was simply exercising his legitimate trade union rights.
2015 was characterised in Iran with increasing numbers of protests and strikes by teachers, campaigning for more money for education, democracy and the right to organise.
Education International is demanding the release of Mr Abdi. Four other teachers' leaders are also in prison, Ali Akbar Baghbani, Rasoul Badaghi, Alireza Hashemi and Mahmoud Beheshti Langroudi.