In recent days headteachers at infant and nursery schools across France have noticed a concerning drop in the number of children attending classes.

The reason for such a high and unexpected rate of non-attendance was not down to the stomach flu epidemic that is sweeping France but something far more sinister.

Last week parents in various parts of the country began receiving strange text messages, that said classes in sex education, masturbation and in gender theory were to be given at school and told them to keep their sons and daughters at home on either Friday or Monday as a protest, French daily Libération reported. 

"Sex education will be provided in nursery schools in September 2014, with demonstrations,” was one text. Another was “Now they are talking about teaching children aged four, how to masturbate," Est Republicain reported.

According to the certain reports the texts were specifically directed at Muslim parents.

“The state is going to teach our children that they were not born a boy or a girl like God wanted, but they are whatever they choose to become. With gay and lesbian speakers who will fill their heads with monstrous ideas,” read part of another text.

The messages appeared to have their desired affect, with union leaders telling The Local that up to 50 percent of pupils in some school were absent on Monday.  

A director one nursery school in Strasbourg told France's Huffington Post that he had been bombarded with telephone calls from angry parents.

"I heard everything. Apparently we were going to invite gay and lesbian speakers who would explain to children how to kiss. Jewish associations were going to come and tell children they could change sex if it did not suit them and schools were going to show porno films. Which is all entirely false," the headteacher said.

Around 80 children were absent the next day despite his efforts to convince parents the rumours were false.

According to Le Parisien, 20 percent of French parents in the town of Meaux, near Paris, kept their children off school after the same scaremongering message did the rounds there.

“We rang one mother last Friday to find out what was wrong and she showed us the text message,” a school headteacher from Brittany told Ouest-France. “We spoke to her and reassured her,” she added.

Rumours that teachers were to give classes on the benefits of masturbation have also been circulating on various right-wing websites.

One article even wrote that France has adopted a World Health Organization (WHO) report that proposes to encourage child masturbation to allow them to express their “sexual needs and desires”.

'Anti-gay marriage campaigners behind hoax'

According to Libération, the origin of the “crazed rumour” and call to boycott schools appears to be writer Farida Belghoul, a close acquaintance of the far-right essayist Alain Soral, who was one of the leading campaigners against gay marriage.

Belghoul took part in the “Day of Anger” protest in Paris on Sunday that was made up of various right-wing groups who had been opposed to the legalizing of same-sex unions, known as "Marriage pour Tous" (Marriage for All).

Belghoul has taken issue with a new government initiative called the “ABCD of equality in school”, which has nothing to do with gender theory but will be trialed in September and is simply aimed at teaching equality and respect between boys and girls from a young age.

She claims however it has a hidden ideological agenda which may make children question their sexual identity and has set up a collective to campaing against the initiative.

The reports have angered teaching unions, whose members have spent recent days trying to put parents fears at ease. 

"It's disgraceful what has happened. We have had a real battle to convince parents that it is not true," Michelle Olivier, from France's SNUiPP teaching union told The Local on Monday.

"We have asked the minister to issue a statement in order to put parents minds at ease," she said. "We are concerned this may continue, with those behind it promising further campaigns in the coming months.

"It is completely normal to teach equality to young children in order to help them accept it," she added.