Mr Zemmour, who has been likened to Donald Trump for his populist politics and controversial statements, said Marseille had been “disintegrated by immigration” and that if nothing was done the whole of France would, in an initial phase, come to resemble the city.
Marseilles has been the location for gang violence and, last month, a row over striking dustmen.
In a later phase, France was set to look “like Lebanon”, he said, as the Middle Eastern nation suffers acute energy and currency crises. He dismissed claims that Marseille was a cosmopolitan city as “a myth”.
Left-wing media such as France’s la Libération newspaper speculated that the Marseille escapade could spell the end of Mr Zemmour’s dramatic rise.
He is expected to officially declare his candidacy for the 2022 presidential election next week and hold a Paris rally in early December.
While his popularity, as indicated by polls, has slipped in recent days, the outcome of next April’s presidential elections is still far from certain.
France elects its president across two rounds of voting, with incumbent Emmanuel Macron expected to make the second round.
Mr Zemmour’s outburst reminded some of former president Nicolas Sarkozy, who famously told a man who refused to shake his hand casse-toi, pauv con or “get out of here, a—hole”, during a visit to a farmers’ exhibition in 2008.