Patrick Roach has announced he is not seeking a second term as general secretary of the NASUWT teaching union and will be standing down in the new year.
He was chosen as general secretary in 2019 and took over the following year from his predecessor Chris Keates.
The union will now start the process of electing a new general secretary, with nominations for the post closing in March 2025.
Dr Roach said: “The last 15 years witnessed one of the most difficult and turbulent periods for the teaching profession, but throughout we have continued to deliver support, protection and a stronger voice for our members at work.
“Now, new opportunities lie ahead to secure a new deal for teachers and our mission of putting teachers first.”
He said that the election of a new government this year would give his successor a chance to “make their mark”.
NASUWT national president Rashida Din said: “After 15 years as both NASUWT general secretary and deputy general secretary and many years as a diligent and outstanding member of staff, Patrick has decided now is the time to step down from his role as a champion of the teaching profession.
“He will be sorely missed within the NASUWT family and beyond, both within the UK and international trade union movement and across the education sector.”
Dr Roach had “not only been a staunch defender of working rights for teachers” but deserved wide recognition for “his campaigning against all forms of discrimination and injustice”, she added.
She also paid tribute to work as chair of the TUC’s Anti-Racism Taskforce.