Almost half of all autistic children “have been illegally excluded from schools because teachers cannot cope with their behaviour”, a report has revealed.

New figures from autistic spectrum disorder (ASD) charity, Ambitious About Autism, suggest that more than 20,000 autistic children in England have been unlawfully put on a reduced timetable, sent home early, or asked not to go into school on days when tests or trips were happening.

These exclusions are illegal when the school does not provide the official paperwork, the report reveals.

It found that children with autism are four times more likely to be permanently excluded from school than any other child, and almost a quarter of respondents (45 per cent) were formally dismissed at some point.

The charity said: “Not only do children with autism miss out on vital school time because of illegal exclusions, but by going unrecorded or reported the scale of the problem is hidden, making it harder for families to stand up for their children’s rights.

“We know that illegal exclusions are commonplace, with 33 per cent of school leaders confirming that they knew at least one child with autism who had been excluded from their school illegally in the last year.”

Jonathan Andrew, chair of the charity’s youth council, said he was “shocked and appalled” that young people with autism “could be let down in this way”.

He added: “Every child deserves access to a good quality education, and children with autism are no exception.”