Schools are becoming increasingly segregated along class lines, a teacher's leader has warned – calling spending cuts and reforms that hit poor pupils the Coalition's "dirty little secret".

The poorest children are suffering most from the "toxic" effects of socially divided schools, according to the head of the Association of Teachers and Lecturers. "We have schools for the elite; schools for the middle class and schools for the working class," said Mary Bousted. "Too few schools have mixed intakes where children can learn those intangible life skills of aspiration, effort and persistence from one another."

Dr Bousted told her union's annual conference in Manchester yesterday: "This Coalition Government's attack on poor children is a blight upon our conception of ourselves as a civilised society. They remind me of a former Prime Minister who said there was no such thing as society."

Cuts which had affected the poor, she said, included:

l A 22 per cent cut in grants to Sure Start centres for under-fives, leading to the closure of 124 centres;

l The withdrawal of education maintenance allowances of up to £30 a week which encouraged poorer students to stay on in post-16 education;

l The removal of the ring-fence on school meals funding at a time when the number of children entitled to free lunches has risen by 110,000;

l Cuts in local authority grants which have led to one in five councils axing the supply of library books to primary and secondary schools;

l A real-terms cut of 13 per cent in education spending by 2014-15.

Dr Bousted said: "If you are a child in a poor family, that is how you will feel now in 2012 – that you are on your own, alone with your parents or carers, with precious little help available, even though it is desperately needed."

She suggested schools were being used as scapegoats for problems in the system, and ministers and the Ofsted inspectorate were ignoring their responsibilities. "The Secretary of State ... and his ministers and his hand-picked [Ofsted chief inspector] are pulling a con trick," she said. "They are seeking to wash their hands, like Pontius Pilate, of all the causes of educational failure over which they have more control than anyone else."

"In Michael Gove and Nick Gibb's world, it is the school, and only the school, that holds responsibility for the educational outcomes of the poor. If the poor do not make as much progress as the rich, it is the school and the teachers within it who are to blame. This, as you and I know, is a nonsense.

The Department for Education accused Dr Bousted of "defending a culture of underachievement".