Schools are being marked down by Ofsted inspectors because parents are sending their children in with unhealthy packed lunches, a Black Country Labour MP has warned.

Wolverhampton South West’s Rob Marris wants the Government to order Ofsted to stop the “unfair” assessment. Schools minister Diana Johnson said she would raise it with Ofsted chief inspector Christine Gilbert.

She said packed lunches were the responsibility of parents, not the school.

At Commons question time, Mr Marris said: “It is unfair that Ofsted marks down any school where a high proportion of parents choose to send their children to school with unhealthy packed lunches, despite the school’s efforts to educate parents about healthy eating. Will the Government order Ofsted to desist and if not, why not?”

The minister said: “Packed lunches are the responsibility of parents and the majority of parents do provide a balanced packed lunch.But it is the responsibility of parents, not the school.”

Nicholas Sullivan, head at East Park Infants School, Hollington Road, said today he agreed with Mr Marris.

The school was judged “outstanding” and commended for children’s understanding on health.

Mr Sullivan said: “It is ultimately up to the parents to take the lead if schools have made every reasonable effort.” The pupils’ school council decided crisps should be kept at home.

Amarjit Cheema, head at Woodfield Infants School, Penn, said: “I can certainly empathise with any headteachers that have found themselves in this position, although it is not a problem here. We are here to educate children but there will be some who simply will not eat anything but unhealthy foods and we cannot force them to do otherwise.”

Wolverhampton is the first area trialling a scheme offering more free school meals. Families with total income less than £16,040 can apply under the £6 million two-year scheme.