The minister, Marlène Schiappa, confirmed her Government’s choice after conducting public consultations during an “equality tour” and commissioning an expert report on the issue.
Adult sex with a minor below the age of 15 is currently classified as sexual assault or molesting, in France.
The offence is punishable by up to five years in prison, compared with the 20 years for rape.
Adults who wield some form of authority over the child face stiffer sentences but the law does not automatically treat such cases as rape unless there is proof of force.
Last Autumn, the Government promised change after an uproar over rulings said two 11-year-old girls were not raped by much older men because they had allegedly agreed to sex.
A 30-year old man was acquitted after the court determined the girl had not been subjected to “constraint, threat, violence or surprise” in one of the cases.
In the other, prosecutors decided the 28-year old man should be tried for molesting – but not rape – as there was no sign of resistance.
After a negative response, judges embarked on new inquiry into “rape of a 15-year-old” last month.
In December, a French school teacher was given a suspended sentence for sleeping with a 14-year old pupil.
The prosecutor went on to asked for a five-year prison term – with two years suspended – and overruled a request for further investigations from the girl’s family.
Her parents argued police had failed to grasp the importance of the case, treating it as a “simple love affair.”
The relaxed approach to teen and adult relationships has long been accepted in France.
President Emmanuel Macron met his future wife Brigitte when he was around 14 and she taught at his sixth-form college, aged 38.
The pair started dating when he was 16.
In December, Mr Macron said he would push for the age of sexual consent and presumption of rape to be set at 15.
He said: “Our criminal law contains intolerable ambiguities.
Though he feels France does not have a puritanical society, he did say the country’s “entire society is sick with sexism.”
During talks over many of the issues, some people felt the age beyond which sex with a minor should be considered rape should be 13.
The expert panel concluded that an adolescent “deserves reinforced protection up until the age of 15 or 16 due to the deep marks triggered by sexual trauma on the functioning of the brain.”
The change is part of a wider law “against sexist and sexual violence” that will be presented to the council of ministers on March 21st.
Under the new law, men who harass women on French streets will risk immediate fines between €90 (£79) and €750 (£670).