23/07/2015 12:24 BST | Updated 23/07/2016 06:12 BST

Diary Of A Teenage Girl Makers Attack Film's 18 Certificate

The director and makers of a new "coming of age" teenage movie have hit out at the decision to give it an 18 certificate.

The movie in question, The Diary of a Teenage Girl, has been issued the age rating by the British Board of Film Classification (BBFC) due to the "theme and manner" of the film. 

The synopsis describes it as "not only a film about a young woman but most importantly a film made for young women; something not often seen in today's male-dominated landscape".

According to a statement from the film makers, the sexual relationship between the 15-year-old-protagonist and the 35-year-old boyfriend of her mother, is the main cause for concern.

They say they are fighting the decision after "the film was re-watched only by men".

They went on to cite examples of other movies such as Fish Tank, Kidulthood and The Reader, all of which they say feature under-age sex, and were awarded certificates of 15.

Director Marielle Heller said: "A girl's coming of age is rarely seen on screen or given the same treatment as a boy's. The media has endlessly told teenage girls that boys are the only ones who are going to want sex. Girls are going to be the ones that don't want it."

She went on to say: "As girls, we have been trained for a long time to relate to a male protagonist, to feel their stories and to be invested in them. And there's no reason why we can't invest in female characters the same way.

"Sexuality is something we're both experiencing and so if one side's perspective is reflected, the other side should be reflected too. Women's stories should be explored and celebrated too."

Vertigo Releasing said in a statement: "We are massively disappointed with the final ruling. The film has been viewed by men at the BBFC and we feel that they have missed the point of the film and its message.

"The film explores female sexuality with boldness and honesty in an un-exploitative manner.

"In an age where young women are still continually being sexualised and objectified we feel The Diary of a Teenage Girl sends a very positive, reassuring message to young girls about female sexuality and body image. It is a shame that audience will not be able legally to see a film that was made by women for women of all ages."

A statement from the BBFC said: "Diary of a Teenage Girl has been classified 18 for 'strong sex'. The sex scenes and references are too numerous and sustained for a 15 classification to have been defensible."

The movie stars Bridesmaids' Kristen Wiig and True Blood star Alexander Skarsgard.