The Virgin Primary School in Hartfield will be hosting the transgender day before the Easter holidays in order for pupils to have discussions about gender and sexuality.
Headteacher Emma Maltby has defended her decision, telling the East Grinstead Courier; 'As part of the national curriculum, we spend time talking to the children about British values of tolerance, respect and celebrating differences.'
The one-off lesson is planned for students throughout the school, including reception students aged as young as four years old.
Emma added; 'One of the areas we will be discussing shortly is gender identity and we felt that it was important to involve parents in their child's learning by holding an information session.'
It's been reported that as many as 10 families have chosen to keep their child at home on the day of the event, although the school officially says it's three families.
Others have been more supportive of the plans, Emma said; 'We have had a very positive response to the event and the opportunity to learn more about this relevant topic.'
One parent, who spoke to the Mail Online, but chose to remain anonymous said; 'I don't want my daughter to be exposed to all this nonsense. Kids need to be left alone when it comes to things like this.
'They just want to run around the playground not to be told they need to "think differently" about gender issues.'
The day is centered around a project called Allsorts Youth, which is based in Brighton and encourages young people to talk openly about gender.
In January 2016, Brighton College secondary school became the first school to scrap distinctions between boys and girls uniform allowing transgender pupils to wear a suit or a skirt.
The co-educational independent school said that at least one pupil had taken up the option and several more families were interested.