In a report published this week, Newtown high school, in Powys, was judged to have serious weaknesses. Estyn, the Welsh inspectorate, singled out the behaviour and attitude of the pupils as particularly unsatisfactory. Though most teaching was judged to be satisfactory, the standards achieved by pupils fell significantly below national targets. Pupils’ speaking and listening skills were also deemed unsatisfactory.

Gethin Lewis, Welsh secretary of the National Union of Teachers, described the Estyn report as one of the worst he had seen. In a statement, he has called for the head of Newtown to resign.

“A crisis exists in the school as a result of a breakdown in the disciplinary structure,” he said. “The school is like a ship which has crashed on the rocks. Sadly, no one believes the captain has the leadership qualities to steer this ship.”

Brian Harris, chair of governors for Newtown, accepts that the school has serious faults. But he insists that these can be remedied under the current management team.

“It hasn’t crossed our minds to bring in new senior management,” he said.

“We are working with them, staff and the local authority to prepare a detailed action plan. There’s nothing fundamentally wrong with the school that cannot be put right if it is focused on.”

Glyn Hughes, head of Newtown, has taken extended sick leave. John Dunford, general secretary of the Secondary Heads Association, says that he is outraged by the NUT’s statement. “SHA deplores in the strongest possible terms this public professional assassination of a headteacher by the NUT,” he said. “It represents a deplorable naming and shaming of a headteacher.”

Mr Harris said such bickering between unions is not helpful to his school:

“It will only distract from what we are trying to do.

“I have to look after the morale of staff. They are the ones who are going to be inspected again in a year.”