The Head teacher at one of the UK’s most successful schools says it is the “boy free” environment that helps her students thrive.

Rhiannon Wilkinson, head at Wycombe Abbey School, also said single sex schools provide protection from a “highly sexualised world” and allows girls to focus on their studies.

Wycombe Abbey is rated as the number one all-girls boarding school in the UK in terms of top A Level grades and is ranked third nationally overall with 90.67 per cent A* and A marks.

And Ms Wilkinson insists the impressive performance of pupils at the £34,000-a-year school is partly down to the absence of the opposite sex.

She told the Telegraph: “My wide educational experience in both mixed and girls' schools has shown me clearly that girls are best served educationally in their teenage years in a boy-free work environment. 

"Most psychological studies suggest that girls and boys develop at different rates and that girls are far in advance of boys through the teenage years: it is in a girl's best interests to be educated separately, at least until boys catch up with her.

“In co-ed environments lots of girls when adolescence kicks want to be liked by boys not just for their intelligence and want to be popular with boys.

“In a girls environment you’re free from that. Most of the time you're focusing on your education, on who you are, you don’t feel you're not being yourself in the classroom, you're not afraid to throw yourself in the sport field.”

League tables of the top grades show that the top three schools in the country at GCSE level are all-girl, as well as six of the top ten.

548-pupil Wycombe Abbey is third in this list, with 98.66 per cent of pupils receiving receiving all As or better in last year’s exams.

Ms Wilkinson has also stressed the importance of single-sex boarding schools acting as a sanctuary away from the increasing pressures of modern life on children.

Echoing comments made by Eton head Tony Little last month, she said: "Girls in single sex schools thrive, they remain girls for longer, these places provide a bit of protection, a bit of relief from a highly sexualised world.

“Boarding schools are wonderful havens and oasis where girls can be happy and achieve what they need academically."

One of the few counties to pursue the grammar school system, Bucks has a number of single sex schools, with only Chesham Grammar School and Marlow's Sir William Borlase schooling girls and boys in classes together in the south Bucks area.