The practice of moving students with special educational needs to other schools during Ofsted inspections is “widespread”, according to new research.

A report by University of Cambridge professors Maurice Galton and John MacBeath on special educational needs (SEN) and disability provision concludes that many schools are denying places to pupils from vulnerable backgrounds.

The document, due to be published today by the NUT during the union’s annual conference, criticises the “considerable variation” in the approach used by different inspection teams, before highlighting the lengths schools go to in order to attain a positive report.

“Decanting children with special needs to other schools prior to an Ofsted visit appeared to be widespread and was mentioned routinely in most of the schools visited,” it says.

The report was based on an “in-depth” study of 19 schools visited by the Cambridge researchers.

Ofsted “continued to have a momentous and disproportionate impact on school life and a specific impact on the numbers of children with SEN that schools felt able to include,” the researchers said.

“Nor was the ‘changing the goalposts’ by Ofsted seen as helpful - it required constant changes of strategy to keep up with the rapidity of central policy shifts.”

One primary school’s SEN co-ordinator told the researchers: “I am afraid that [Ofsted] are data driven. I’ve done case studies on children, the things we’ve done, the progress they’ve made, the problems they’ve had, so I feel confident that I can defend what we do…but who knows?”

The report also says there is less support available from local authorities for SEN students.

NUT general secretary Christine Blower said SEN students were being “badly let down”.

“They face discrimination in admissions practices in some schools. Local authorities can no longer ‘hold the ring’ and ensure schools work together on special needs.

“Schools face an accountability regime which undermines inclusive education and which is jeopardising some of the world-class inclusive practice developed in our classrooms,” she added.