The comments by Éric Zemmour, who has previously been convicted of inciting racial hatred, prompted outrage and led to him being dropped from an 11-year stint on a chat show.
But many sprang to the best-selling author's defence including the far-right National Front leader Marine Le Pen, who declared the move 'loathsome censorship'.
Mr Zemmour's interview with Italian newspaper Corriere della Sera went largely unnoticed on the other side of the Alps for more than a month after it appeared in October.
It sparked a public debate, however, after the comments were picked up by former French education minister Jean-Luc Mélenchon.
Although the original interview has been deleted from Corriere della Sera's website, it was copied and translated several times by people on both sides of France's political divide.
In the interview Mr Zemmour said Muslims 'live among themselves' in suburbs which French people have been forced to leave, according to one of his supporters.
The interviewer then asked: 'Then what are you suggesting? To deport 5million French Muslims?'
Mr Zemmour is said to have replied: 'I know it's unrealistic, but history is often surprising.
'Who would have thought in 1940 that a million pieds-noirs [Europeans living in North Africa], twenty years later, would have left Algeria to return to France?
'Or that after the war five or six million Germans would leave Central-Eastern Europe where they had lived for centuries?'
The interviewer protested that Mr Zemmour was 'speaking of exoduses triggered by immense tragedies', to which he replied: 'I think we are heading for chaos.
'This situation of a people inside a people, of Muslims inside French people, will lead us to civil war.
'Millions of people live here in France and refuse to live in the French manner.'