Conservative opposition party leader Laurent Wauquiez’s comments come after Corsican leaders said they wanted their language to be officially recognised, as well as for jailed militants to be returned home and for foreigners to be banned from buying holiday homes on the island.
Mr Wauqiez said: “There is a red line that cannot be crossed: Corsica is and will always be French…
“We’ve seen what happened in Catalonia, and so we know full well that the issue [of greater autonomy] is one we need to follow closely.”
Speaking to the French public television channel France 2, the head of the centre-right The Republicans party, added: “This means that there is no such thing as a Corsican citizenship and that the Corsican language cannot be put on equal footing with the French language.
“We need to respect the attachment to Corsican identity, but Corsica’s integration in the French republic cannot be questioned.”
Separatist sentiment intensified in December after the nationalist alliance Pè a Corsica (For Corsica) won two-thirds of seats in regional elections.
However, unlike their Catalan counterparts Corsican nationalists have steered clear of seeking outright independence from France, asking instead for “more autonomy”.
This is because while Catalonia is wealthy and self-sufficient, Corsica is one of the poorest regions in France and relies heavily on funding from Paris.
Corsican nationalists have issued three core demands: equal recognition for the Corsican language, the return of jailed political prisoners to Corsica from mainland France and the recognition of a special residency status for Corsica to stop foreigners from buying holiday homes on the island.
French ministers, however, incensed nationalist leaders last week by refusing several of their demands, including official status for the Corsican language.
Regional parliament speaker Jean-Guy Talamoni said: “Our goodwill has been taken for weakness by Paris, but we are not weak, we are strong…Corsicans want to be recognised as a nation.”
Unlike its neighbours Spain and Germany, France has always been reluctant to give much freedom to its regions, despite some decentralisation in the 1980s.
French president Emmanuel Macron arrived in Corsica for a two-day visit on Tuesday, where he is expected to address the growing calls for more autonomy from Paris.
Mr Macron will first pay tribute to the late prefect Claude Erignac, a top official who was shot dead by pro-independence activists 20 years ago.
He is then expected to meet with nationalist leaders Gilles Simeoni and Mr Talamoni.