Last night, UK doctors and politicians called on schools to halt the move towards unisex toilets to prevent further harm to female pupils.

Schoolgirls are refusing to use gender-neutral school bathrooms, putting their health at risk by not drinking enough and refusing to urinate.

“GP Tessa Katz said holding in urine for prolonged periods on a regular basis could increase the risk of girls suffering urinary and bladder infections.”

Girls are also taking days off when they have their period rather than share a bathroom with boys.

Parents at one UK school have started a petition opposing its gender-neutral toilets, upset they weren’t consulted about the bathrooms.

One angry mother, who has daughters aged four and eight at the school, said: 'The cubicles were open at the bottom and top so older pupils can easily climb up the toilets and peer over.'

Stephanie Davies-Arai, from the parent campaign group Transgender Trend, said schools were being misinformed by 'trans activist' organisations that they were breaking equality laws if they did not make toilets unisex.

She said there were clear exemptions under the current equality laws that meant it was perfectly legal to have single-sex toilets.

Kirralie Smith, Binary spokeswoman, applauded the parents taking action.

“Transgender activism is causing these girls anxiety and putting them at risk.  Encouraging males to use spaces reserved for females is dangerous.  Parents and other authority figures have every right to be concerned for the welfare of their girls.”

“It is essential that the safety and health of the students take preference over appeasing radical activists.”