A row flared up in March when janitors took industrial action in protest against council cuts, forcing a third of the council’s schools to close. Edinburgh had expected headteachers to open schools normally, which the Association of Head Teachers (Scotland) claimed meant they had to man boilers, serve lunch and take on other responsibilities which were not part of their job.

Rena Mitchell, the association’s president, said its Edinburgh officials agreed there was no legal basis for this. But revised guidelines made no real difference and recourse to an industrial tribunal was now a real possibility, she said. The Educational Institute of Scotland supports the heads’ case.

John Dobie, Edinburgh’s depute director of education, has told the association that headteachers automatically become the school keyholder in the absence of the janitor or caretaker, and assumed responsibility for the health, safety and security of the premises.

But Jim Smith, the association’s secretary, said: “A headteacher is not contractually obliged to take on these duties.” Responsibility for the management of a school was quite different from responsibility for its security.

Kirsty Jack, head of Corstorphine primary and convener of the AHTS in Edinburgh, said her colleagues were simply looking for “the authority to be managers in their own schools to meet local circumstances as they arise”.

Mr Dobie said the assumption must be that heads would attempt to keep schools open unless there were good reasons for not doing so. Clear guidelines had been issued for consultation which require heads to discuss any potential closure with education officials before a final decision is taken. He feared a legal challenge from parents if there were “blanket closures”

Mr Dobie said the council was prepared to agree that emergency call-outs at night should be undertaken by janitors. “Whoopee,” Mrs Jack said.