Former prime minister H D Deve Gowda on Wednesday said he was opposed to the Citizenship (Amendment) Bill as "it will totally destroy minorities and is unconstitutional".
Talking to PTI over phone, the Janata Dal (Secular) president said the Bill was contrary to the principles of secularism and other rights incorporated in the Constitution.
"You can't go against secularism and other constitutional principles," he said.
"I can't support such a Bill" as it would create "unrest" in the country, he added.
The Citizenship (Amendment) Bill, which seeks to provide Indian citizenship to non-Muslim migrants from Pakistan, Bangladesh and Afghanistan, was passed by Rajya Sabha on Wednesday. Lok Sabha cleared the Bill on Monday.