Your own Interior ministry estimates 5-6 million muslims in France, about 10% of the population. Considering their birth rates are higher than most of the native Europeans, in 20 years time that demographic will have changed dramatically.
Ok, mythbusting time: First a comment about immigrant reproduction; Most imigrants have an elevated rate of reproduction (compared to the native population) in the generation that arrives, this drops off rapidly and by the 3rd generation the birth rate is generally the same as the native european one, so no, in 20 years the muslims will not be a majority. Added to which you have a rate of apostasy, in france that's about 20%, most of which are women, ie, the breeders. It is also worth noting that exactly the same arguments were being bandied about in 20's Germany concerning the Jews.
A comment concerning religion; In France the rate of atheism is at a little over 50% of the adult population and increasing every year, so while the number of muslims may be increasing, it does so mostly at the cost of christianity, and has a snowballs chance in hell of becoming the dominant power in a majority atheist state. Religion in general is dying out in europe, the recent influx of more radical islam is only accelerating the process of disilusion with such antiquated ideas.
A comment on the muslim populations in europe; Pre 2001, the great majority of muslim immigrants came from the educated, liberal sectors of their society, those who wanted to live in a secular nation. Despite the monochrome idea many have concerning islam, a great many european muslims are just like the catholics here in spain, ie they identify themselves as muslim, celebrate the major festivals, use muslim traditions for weddings and funerals and pretty much ignore the rest of the mumbo-jumbo the fanatics take so seriously. You just have to look at the average terraza
on the beach here in Spain to see muslim women in bikinis, drinking cold beer with their husbands and behaving just like any other holidaymaker.....