Union home minister Amit Shah will on Monday introduce the contentious citizenship (amendment) bill in the Lok Sabha, a move that is likely to trigger parliamentary showdown over the draft legislation that proposes Indian citizenship for non-Muslim refugees from Pakistan, Bangladesh and Afghanistan.

The bill proposes to give citizenship to Hindus, Sikhs, Buddhists, Jains, Parsis and Christians if they entered India from the three nearby countries on or before December 31, 2014.

North-eastern student organisations, civil society groups and opposition parties have been protesting the government's move, saying it will lead to an influx of religious minorities and hurt the interests of indigenous communities in the region.

Watch | Explained | Citizenship Amendment Bill: The content, the controversy

The Union Cabinet cleared the bill last week, fulfilling a key election promise of the ruling Bharatiya Janata Party (BJP) but several opposition parties said they continue to oppose the draft bill, which they said linked citizenship to religion and therefore violated the Constitution.

The Congress's parliamentary strategy group held a meeting at party president Sonia Gandhi's residence and decided to strongly protest against the bill in Parliament. "The Congress will oppose the citizenship amendment bill tooth and nail in Parliament as it is against the country's Constitution, secular ethos, tradition, culture and civilisation," the Congress's leader in the Lok Sabha Adhir Ranjan Chowdhury said after the meeting concluded.

CPI(M) general secretary Sitaram Yechury said his party will move two amendments on the bill when it is introduced in the Lok Sabha. "We strongly oppose the Citizenship (Amendment) Bill which gives citizenship on the basis of religion, that also to people from three countries," Yechury said. He said that India is home equally to all religions and that people of all religions must get equal treatment.

On Sunday, a protest against the bill turned violent when a group of people in Dibrugarh vandalised an office of the Asom Gana Parishad (AGP), an ally of the BJP in Assam. Sixteen organisations have called for a 12-hour bandh in the state on December 10 to protest against the National Democratic Alliance (NDA) government. People in the region strongly opposed a previous version of the bill earlier this year.

The protesters feel that the draft bill will dilute the Assam Accord that promises deportation of any illegal foreigners who arrived after March 24, 1971, a day before the war of liberation in Bangladesh began. The AASU and 30 other organisations said they will hold demonstrations against the bill.

The government has said the draft bill, which seeks to amend the Citizenship Act of 1955, is aimed at three goals: equity, accountability and innovation; and that the bill will apply to those people "who were forced or compelled to seek shelter in India due to persecution on the ground of religion or fear of such persecution in his country".

Speaking at an election meeting in poll-bound Jharkhand, Union minister and senior BJP leader Rajnath Singh criticised the stance of the opposition parties that have sought the withdrawal of the bill. Countering the allegation that the government's move was divisive, Singh said: "The BJP does not discriminate people on the basis of faith or caste."

The Shiromani Akali Dal hailed the NDA government's decision to introduce the bill in Parliament, saying a long-pending demand of the party has been accepted. It, however, said the bill should cover all persecuted people irrespective of their religion.

On Monday afternoon, the home minister will introduce the bill to amend the six-decade-old Citizenship Act and it will be taken up for discussion and passage later in the day, according to the Lok Sabha's list of business. Both the Congress and the BJP have issued whips to their members in the Lower House to remain present from December 9 to 11.

The draft bill says that all criminal cases for illegal migration against religious minority groups seek refuge in India will stand abated and they will be deemed to be Indian citizens from the date of their entry into the country. Such people will be naturalised citizens.

In addition, the number of years required for obtaining naturalised citizenship of India is proposed to be reduced from the current 11 years to five years.

There are two notable exceptions that were absent in the previous version of the bill that passed in the Lok Sabha in January but triggered massive protests. The first are the tribal areas under the Sixth Schedule of the Constitution, which deals with autonomous tribal-dominated regions in Assam, Meghalaya, Tripura and Mizoram.

The second are areas covered under the inner-line permit (ILP) regime, under which non-locals need prior permission before visiting these areas. Such regions exist in Arunachal Pradesh, Nagaland and Mizoram.

The draft bill also empowers the government to withdraw someone's Overseas Citizenship of India (OCI) status if they violate any provision of the new Citizenship Act or provisions of any other law.

Providing citizenship to minorities from Pakistan, Bangladesh and Afghanistan was a key election promise of the BJP, which has been vocal in the past about the alleged persecution of Hindus in these countries. The bill was first introduced in 2016 and passed the Lower House in January but was stalled in the Upper House, where the government lacks a majority.

A top official said the bill was reworked by the Union home ministry after home minister Amit Shah held several rounds of negotiations with social groups, political groupings and representatives from the north-east.

(With inputs from agencies)