Maharashtra Chief Minister Devendra Fadnavis and state Congress president Ashok Chavan paid tributes to union minister Ananth Kumar, who died in Bengaluru in the early hours of Monday.
Mr Fadnavis said he was "shocked and deeply pained" by Ananth Kumar's "untimely" demise.
"His contribution towards society, service to the people will be remembered forever. My deepest condolences to his family, friends, followers, karyakarta," the senior Bharatiya Janata Party (BJP) leader said in a tweet.
Senior Congress leader Ashok Chavan also took to the micro-blogging site to express grief over Ananth Kumar's death.
"Deeply saddened by the passing of Union Minister, Shri Ananth Kumarji. My condolences to his family & friends. May his soul rest in peace," the former Maharashtra chief minister tweeted.
Ananth Kumar, 59, a six-time parliamentarian, died at a private hospital in Bengaluru after battling lung cancer for several months, hospital authorities said.
He is survived by wife and two daughters.