David Evans, Secretary of the National Union of Teachers (NUT) Cymru, said they back the comprehensive schools system fully.
He said "it suits us - its suits the people of Wales - it suits the children of Wales."
The last grammar school in Wales closed in 1988, but the Welsh Conservatives are calling for a return to the grammar system.
More top news
Sunshine in the north this evening, but cloudy in the south.
Hundreds of people gathered in Cardiff for International Yoga Day. Young and old came together to learn about the ancient Indian discipline
Liam Williams admitted that he loves "having a run" after setting up one of the greatest tries in British and Irish Lions history.