NEW DELHI (Reuters) - A small regional party in India quit Prime Minister Narendra Modi’s ruling coalition on Monday, protesting against his bid to give citizenship to hundreds of thousands of non-Muslims from neighboring countries such as Bangladesh.

Activists from the All Assam Students Union (AASU) shout slogans during a protest against the government's bid to pass a bill in parliament to give citizenship to non-Muslims from neighbouring countries, in Guwahati, India January 7, 2019. The placard reads "Citizenship Amendment Bill 2016". REUTERS/Anuwar Hazarika

Modi said last week his government was determined to pass a bill in parliament to relax rules for Hindus and other non-Muslim minorities from Bangladesh, Pakistan and Afghanistan to become citizens of Hindu-majority India.

Critics have called the bill, to be discussed in parliament on Tuesday, an attempt by Modi’s Hindu nationalist Bharatiya Janata Party (BJP) to boost its Hindu voter base ahead of a national election due by May.

The Asom Gana Parishad (AGP), based in the border state of Assam in India’s northeast, has become the fourth ally to quit the ruling National Democratic Alliance in the past year, for a variety of reasons.

Protests have erupted in recent months and on Monday in Assam, where a movement against illegal immigrants, of all religions, from Bangladesh has simmered for decades, with some residents blaming them for eating into their resources and job opportunities.

It is estimated that millions of Bengali-speaking people in Assam trace their roots to Muslim-majority Bangladesh, which won independence from Pakistan in 1971 with India’s help.

“The home minister clearly told us they will try to get this bill passed tomorrow, so there’s no question us staying with the BJP anymore,” AGP President Atul Bora told reporters in New Delhi.

The BJP has the numbers in the Assam assembly to stay in power in the state despite the AGP pullout, but the regional party could help galvanize anger amongst many ethnic Assamese opposed to giving citizenship to migrants who came to India after 1971.

That could hurt the BJP’s goal of sharply increasing its parliamentary seats from the northeast region of the country in the national election.

At least two of the parties that have left the BJP fold have already largely agreed to ally with the main opposition Congress, which hopes to take on Modi as a united front and says the citizenship should not discriminate against Muslims.

The BJP says it is in favor of institutionalist “constitutional, legislative and administrative safeguards” to the ethnic Assamese, but also wants to give citizenship to Hindus from Bangladesh as the growth in the Hindu population of Assam had been overtaken by that of Muslims.

“We’re trying to save Assam from Jinnah,” BJP leader and Assam minister Himanta Biswa Sarma said, referring to Pakistan founder Muhammad Ali Jinnah who was instrumental in carving Muslim-dominated Pakistan out of India after winning independence from British colonial rule in 1947.