It was recently reported that the Cyrano de Bergerac star wants to move to Belgium for tax reasons following a change in French law.
The new legislation states that anyone earning over €1 million (£813,935/$1.32 million) will face a 75% rate of income tax, and French prime minister Jean-Marc Ayrault was said to have branded Depardieu "pathetic" for buying a property in the Belgian border town of Nelchin.
A letter attributed to Depardieu in Le Journal du Dimanche (via Bloomberg) read: "I am leaving because you consider success, creativity, talent, anything different... grounds for sanction.
"I don't expect to be pitied or praised, but I reject the word 'pathetic'."
Depardieu said that he would surrender his French passport and his entitlement to social security benefits, the latter of which he said he has never used.
Writing that he has been working since the age of 14 and has "always paid his taxes, regardless of the rate, under all governments", the actor said that while he still loves his home country, he feels "insulted" by the new tax law.
"I have paid 145 million [euros in] tax in 45 years, I have 80 people working in companies that were created for them and which are managed by them," Depardieu continued.
"Who are you to judge me? So, I ask you, Mr Ayrault, Prime Minister, [president] Mr [Francoise] Holland, I ask you, who are you? In spite of my excesses, my appetite and my love life, I'm a free man, sir, and I'll keep this polite."