Mrs Horsman is allowed to take her daughter to and from school

Fran Horsman wrote four letters to Loddon Junior in Norfolk, questioning how the school, which her 10-year-old daughter Gaby attends, was run.

Chair of school governors Chris Boswell said Mrs Horsman, who was a parent helper, could come to school events with the head's permission.

He said he was sad the relationship had broken down but he stood by the ban.

Mrs Horsman said she would write a letter to Ed Balls, Secretary of State for Children, Schools and Families.

Her daughter Gaby said: "I don't understand why she is being banned. It's just really weird because other mums and dads are allowed to go in and out of the school but my mum's not."

'Parent's job to question'

Mrs Horsman can only walk her daughter to and from the school - she cannot go inside without an official appointment.

She claimed it was because of the four letters she wrote to the school.

In one she spoke of her "total despair at the general state of affairs", while another said "there is no justification for having every class of mixed year groups".

Mrs Horsman told the BBC: "Part of my job as a parent is to question what goes on at the school and to make sure my daughter gets the best possible education."

A letter from the chair of school governors said the school had consulted its legal team and any further negative correspondence could be viewed as offensive.

Scouts' barbecue

Chris Boswell, chair of governors, said: "I am saddened that the relationship between the school and one of our parent helpers has deteriorated to the extent that the governors have felt it necessary for her to stay away from the site other than to bring or collect her child from school.

"We wrote to the person involved back in July, setting out our concerns, and explaining the basis for our decision.

"If the person concerned wishes to discuss an issue with the school we have asked her to simply make a prior appointment.

"Over the summer the school has had no issue with her attending sports day and a scouts' barbeque for example."