Almost half of children permanently expelled from school last year had special education needs.
That’s according to a National Audit Office (NAO) report, which concludes schools are struggling to support children with special education needs and disabilities (SEND).
Over the same period, funding per pupil dropped by 2.6% in real terms for children with high needs - those in special schools and with education, health and care plans in mainstream schools.
It noted that pupils with SEND are more likely to be permanently excluded from school than pupils without SEND.
The report said: "In 2017/18, children with SEND accounted for 44.9% of permanent exclusions and 43.4% of fixed-period exclusions.
"Evidence also suggests that pupils with SEND are more likely to experience off-rolling - where schools encourage parents to remove a child primarily for the school's benefit - than other pupils."
The report found that, while some children with special educational needs and disabilities are receiving high-quality support, many others are not getting the help they should.
According to the NAO, local authorities are coming under "growing financial pressure" as the demand for supporting school pupils with the greatest needs rises.
The DfE said the Prime Minister has committed an extra £700 million next year to make sure children with SEND "get an education that helps them develop and thrive as adults".
Christine Smith enrolled her autistic son Adam into a mainstream school for the first time last September but he is now in a special needs school in Ipswich.
He will stay at the school for two terms but will then be reviewed with a view to return to a mainstream school.
Ms Smith told ITV News: “There’s not the one-to-one support in mainstream schools for autistic children and special needs children.
“To start with he settled quite nicely but as time went on he struggled more and more and hence the reason why we looked at the reasons why Adam was disappearing from class and it was difficult for staff to keep an eye on him.
“Unfortunately, I don’t think mainstream schools are the right setting for these children. School don’t have the right training there is not enough training out there.”
Gareth Davies, the head of the NAO, said children's needs "are not being met" and called for improvements to quality and sustainability.
Since the report was completed on September 6, the DfE has announced a review of support for pupils with SEND.
Mr Davies said: "Access to the right support is crucial to the happiness and life chances of the 1.3 million pupils with SEND in England.
"While lots of schools, both special and mainstream, are providing high-quality education for pupils with SEND, it is clear that many children's needs are not being met.
"I therefore welcome the Department for Education's announcement last week of a review into support for children with SEND, following our engagement with them on this issue over recent months.
"We hope the review will secure the improvements in quality and sustainability that are needed."
A Department for Education spokeswoman said helping all children and young people reach their potential is “one of the core aims” of this Government, including those with special educational needs.
She added: "That is why the Prime Minister has committed to providing an extra £700 million next year to make sure these children get an education that helps them develop and thrive as adults.
"We have improved special educational needs support to put families at the heart of the system and give them better choice in their children's education, whether in mainstream or special school.
"Last week, we launched a review of these reforms to make sure every child everywhere gets an education that prepares them for success."