Two head teachers have been forced to send letters home after some parents reacted with anger about toilet facilities being locked during lessons.

The policy is operated by Westlands School and Sittingbourne Community College (SCC) – part of the Swale Academies Trust – for health and safety reasons.

Only youngsters with a doctor’s note about a relevant medical condition can freely go to a supervised toilet block during classes.

All other pupils can request permission during lessons and can use the facility as long as they have a note from their teacher.

The rule has been in place at Westlands since 2004 and at SCC since 2012.

But Clare Stevens, whose stepson Kieran goes to Westlands, claims she only heard about it when the Year 8 pupil came home and told her he was initially denied permission by his teacher to go to the toilet because he didn’t have a doctor’s note.

Her posting on a Facebook group to highlight the case provoked 236 comments, the majority of which were critical of the school’s stance.

Westlands head teacher Simon Cox said: “There are extensive toilet facilities around the school for pupils to use at breaktime and lunchtime when staff are on duty to supervise the areas.

"We encourage pupils to get into a routine and use the facilities at these points.

“It is not common sense to allow pupils to use them during lessons when there is no supervision.

"An alternative provision is available to use in between and during lessons and is no more than a two to three minute walk from any other part of the school.

“If parents know their child is ill and might need to use the toilet facility urgently, they are encouraged to contact the school or ideally write a note in their child’s planner so we aware of the situation.”

SCC head teacher Fiona Trigwell said: “Students can use the toilets before lessons start at 8.40am, during break time, throughout lunchtime and after school.

"Toilets are open in the central B block all day long and, although it is not encouraged, students can use these between lessons too. In effect this means they have access to toilets every 50 minutes.

“A student who carries a medical card is allowed to use the toilets at any point throughout the day.

"Students who are unwell would not be sat in lessons feeling poorly but would be in the medical room for an assessment of their needs and whether or not they should be sent home.”