Mrs Kidwell, whose leadership transformed St Luke’s CofE primary in Silverdale, Staffordshire, was taken to hospital last December with suspected ovarian cancer.

She underwent a 12-hour operation to remove a tumour, but while she was recovering she discovered she was under investigation by the local authority.

The tumour was later found to be benign. When she asked to return to her post in May she was suspended, and she was dismissed by the school governors last week.

She has now appealed against the decision, supported by the National Association of Head Teachers.

As The TES went to print, more than 300 parents and community members had signed a petition supporting the “Justice for Jill” campaign and were planning yesterday’s protest.

NAHT regional officer Gary Towler said the grounds for the dismissal were management issues “of a trivial nature”.

He said one of the initial complaints had been that she had not filled in a sickness certificate.

Mr Towler said Mrs Kidwell, 38, has 16 years’ teaching experience and a previously unblemished record.

“She is shocked and disappointed by what has happened, but she is encouraged by the parents,” said Mr Towler.

He said Mrs Kidwell was not aware of any complaints against her before her operation last year, but found out about the investigation when she rang the school in February to thank pupils and parents for their get-well cards.

Mother-of-two Fiona Lawton, who is organising the protest, said: “I think there has been a great injustice done to Jill.”