Baroness Warnock, considered the pioneer of inclusive education, called for more schools to use "nurture groups" - small classes of up to 12 children - in mainstream nurseries and primaries.
Children usually attend the groups, which focus on emotional and social development as well as academic progress, for two to four terms. Speaking at a one-day conference in London on Tuesday, organised by Scope, the cerebral palsy charity, in partnership with The TES, she said: "Nurture groups are useful for children who are emotionally and behaviourally incompetent.
"It's so much easier for teachers when they know a child and see them all the time in small groups to find out what is wrong with them. Nurture groups can make a huge difference and prevent children from being excluded."
Baroness Warnock, who chaired an influential inquiry into special needs in 1978, said nurture groups may not be effective for pupils with serious mental and physical disabilities. "The most seriously disabled will always need special help, but for an enormous group we could eliminate it," she said. "If nurture groups were more widespread they could help reduce the number of children with special needs."
Baroness Warnock said a visit to see a nurture group in Birmingham convinced her of the need. "The children at the group could not really speak or communicate," she said. "One girl asked me whether I liked her. I said yes. She said, 'Mummy doesn't'. She was just astonished that an adult was actually talking to her."