The bill, which is expected to easily pass the lower house of Parliament, would give migrants of all of South Asia’s major religions — except Islam — a clear path to Indian citizenship. It is the most significant move yet to profoundly alter India’s secular nature enshrined by its founding leaders when the country gained independence in 1947.

Muslim Indians are furious and terrified. They see the new measure, called the Citizenship Amendment Bill, as the first step by the governing party to make second-class citizens of India’s 200 million Muslims, one of the largest Muslim populations in the world, and render many of them stateless.

“We are heading toward totalitarianism, a fascist state,” Asaduddin Owaisi, a member of Parliament and a Muslim, said of the bill. “We are making India a theocratic country.”