As the new book by Houellebecq deals with a fictionnal Muslim Brotherhood party in France winning the 2022 presidential election, it has stirred controversy even before its publication on Wednesday.
Houellebecq, 56, imagines an Islamic government in power in France, veiled women and the Sorbonne renamed Paris-Sorbonne Islamic University.
"I can't say the book is a provocation - if that means saying things I consider fundamentally untrue just to get on people's nerves" said Houellebecq in an interview to Paris Review, as he admits the scenario he described in the book is not very realistic.
Nevertheless such a scenario " reflects the fears of the author and also those of society" said academic Franck Fregosi an expert on Islam in Europe.
At the same time, President Hollande on Monday agreed that there was a "serious" identity crisis in France.
It "weighs heavily because the environment is threatening" said Hollande - referring to the terrorist threat - to France Inter radio station.
"We need to keep our nerve and have strong thinking" he added when he commented on recent litterature - with reference to "The French suicide" by French polemicist Eric Zemmour, a book that came out last autumn.
Hollande called on the French people to not react with fear and to defend the "values" of the "Republic" and the French "social model" despite the current climate of doubt.
"Soumission" - "Submission"- is the sixth novel by Houellebecq, who won the Goncourt Prize in 2010 - France's highest literary honour.