'˜Give kids compulsory lessons in relationships'

The finding comes as the Government faces increasing calls for the classes to be mandatory amid growing evidence young people are facing widespread sexual harassment and abuse. Research commissioned by the charity Plan International UK found 85 per cent of those polled think SRE should be mandatory in regular state schools and 84 per cent believe it should be compulsory at academies and free schools.

A total of 83 per cent believe it should be compulsory in private schools and 82 per cent felt it should be in faith schools as well. The survey also found that out of those who received sex education, just 27 per cent found it was informative. This figure drops to just 11 per cent among over-55s, according to the poll.

Tanya Barron, Plan International UK’s chief executive, said: “Girls are telling us that they are suffering harassment at school, they don’t feel safe online and are scared on the street. They are telling us unequivocally that mandatory and good-quality sex and relationships education is one of the most important ways to help change this situation.”

Last year the chairs of five select committees wrote to Education Secretary Justine Greening demanding a change in policy. Maria Miller, chairwoman of the women and equalities committee, who signed the letter, said there was a pressing need for change.

Research last August revealed the number of sex crimes reported at UK schools has nearly trebled in four years.