Damian Hinds is warning schools that exclusion rates are too high and that the government will be investigating the use of the sanction in schools.

The education secretary has said that pupils should only be expelled as a “last resort” and this week will announce a review of exclusions, to be led by Edward Timpson, a former children’s minister.

Mr Hinds said: “I would like to see the number of children who are excluded from school coming down. Although exclusion rates are lower than they were 10 years ago, they have gone up in the last couple of years and it’s really important we understand why.”

A Tes investigation in September found the number of pupils being permanently excluded in some areas had risen by as much as 300 per cent in a year.

Mr Hinds told the Sunday Times that there were big variations in the use of permanent exclusions from area to area and school to school, as well as among groups of children.

His comments follow growing concerns that rising exclusion levels maybe connected with schools trying to “game” the system by getting rid of lower acheiving pupils.

In December Ofsted chief inspector Amanda Spielman used her annual report to warn schools against excluding pupils in order to boost their academic results.

And last month the inspectorate wrote to secondary headteachers in the North and the North East, to express concerns about the high rates of fixed-period exclusions.

There are also concerns about the growing number of back-door exclusions or “off-rolling”. As Tes reported yesterday Department for Education commissioned research has found that 22 per cent of teachers incorrectly think its permissable to put pressure on parents take their child out of school as an alternative to an official exclusion.