Former Law Minister and senior advocate Shanti Bhushan passed away on Tuesday after a brief illness.
Bhushan was 97 years old.
He was a member of the Morarji Desai Cabinet between 1977 to 1979.
Father of activist lawyer Prashant Bhushan and senior advocate Jayant Bhushan, he had featured as counsel in a number of important cases, including in Raj Narain versus Indira Gandhi before the Allahabad High Court, which resulted in the imposition of emergency in the country.
In his message, Prime Minister Narendra Modi said, "Shri Shanti Bhushan Ji will be remembered for his contribution to the legal field and passion towards speaking for the underprivileged. Pained by his passing away. Condolences to his family."
Law Minister Kiren Rijiju tweeted he was "deeply pained to hear the news that...Shanti Bhushan ji is no more."
As Law Minister, Bhushan introduced the 44th Constitutional Amendment Act which repealed a provision of the 42nd Constitutional Amendment Act, which gave unrestrained power to the Parliament to amend the Constitution without judicial review.
He also joined the BJP in 1980 before his resignation in 1986.
Bhushan was also at the forefront of Anna Hazare's agitation and was one of the founding members of the Aam Aadmi Party in 2012.
He, along with his son Prashant, also faced contempt charges for his statement about corruption in the higher judiciary.