CLASS size cuts from the maximum of 33 to 20 throughout primary and secondary were given unanimous support, although delegates once again dismissed any campaign of industrial action to achieve the aim.

Ronnie Smith, the union’s general secretary led the way in his annual address. “If we are serious about social inclusion, about tackling indiscipline, about redressing inequalities, about improving levels of attainment, about getting to know pupils better and fostering the talents of the individual pupil, as the law now requires - I can think of no single, more joined-up measure that would make a difference to all of these goals than a radical reduction in class sizes across all stages.”

It would cost a lot and take time but there was growing evidence that smaller classes improve attainment, especially for younger pupils and children from ethnic minorities.

“Equally important,” Mr Smith said, “there is strong evidence that smaller school and class size have an impact on pupil behaviour. There is evidence that exclusions and truancy decline, that aggressive behaviour is reduced and that classes are quieter and more easily managed.”

May Ferries, past president, reminded delegates that the McCrone agreement stipulated there would be specific research on class sizes. “We know it makes a difference in better behaviour, better learning and reducing the stress on teachers,” Ms Ferries said.