Iruvar is an immortal film directed by Mani Ratnam and supposed to be based on the lives of MG Ramachandran (played by Mohanlal) and M Karunanidhi (played by Prakash Raj), though the makers haven't officially accepted the same.
In an old post, during the demise of DMK Patriarch M Karunanidhi, Malayalam superstar Mammootty had recalled that he was offered the role of Karunanidhi. He had penned: An irreplaceable loss. And the end of a great era. Writer, Author, Screen Writer, Orator and one of the greatest leaders of our time. A revolutionary. But more than all of the many facets to his persona his love for tamizh and his people stand tallest. The opportunity I had to play him in Manis film is something I miss today. All of my meetings with him are fond memories discussing cinema, politics and literature. Deeply saddened by this loss. (sic)
We bet this piece of trivia was known to seldom.