"If the bill in its present form comes into effect, then it will nullify the Assam Accord under which anyone entering the state illegally after March 1971 should be declared a foreigner and deported,"an opposition MP said".
He said, it is the central government's responsibility to protect the identity, culture of the people of Assam.
The proposed Citizenship Bill seeks to provide Indian citizenship to non-Muslims from Bangladesh, Pakistan and Afghanistan.
The Asom Gana Parishad (AGP) on Monday withdrew its support to ruling BJP in Assam over the Citizenship Amendment Bill, AGP president and minister Atul Bora said.
"If the bill is passed, Assam will burn".
The Nagaland Cabinet, on Monday evening, resolved to request the Centre to re-examine and review the Citizenship Bill to ensure it is "in consonance with the provisions of the Constitution and the existing practices of the Nagas".
Trinamool Congress member Saugata Roy slammed the bill, saying it is "divisive".
The protests got a new lease of life after Prime Minister Narendra Modi announced that the Bill would be passed, during an election rally in Silchar in Assam recently.
Another alliance partner, the Bodoland Peoples' Front (BPF), did not come out with any official reaction, but its MLA and Social Welfare Minister Pramila Rani Brahma termed the AGP's decision as "correct", adding that it was her personal view. The move came within hours of the presentation in Lok Sabha of a report of the Joint Parliamentary Committee examining the bill that was first introduced in Parliament in 2016. The North East Students' Organisation and State-based students' bodies in the other north-eastern States joined in while political parties such as Congress and All India United Democratic Front supported the call.
Minus the 14 AGP legislators, the Sonowal government would be left with 73 MLAs, nine more than the majority mark of 64 in the 126-member Assembly. "The AGP protested against the bill ever since it was proposed", the AGP founder said.
CPI-M's Tripura state Secretary Gautam Das, Congress Vice-President Tapas Dey and many other leaders of different political parties apprehend that if the NDA government passes the bill forcefully in the Parliament, a serious resentment would crop up in the northeast.
Police and security forces deployed in Dibrugarh had to fire gunshots in the air and also tear gas to disperse a mob that went unruly in the town, which is home to Assam Chief Minister Sarbananda Sonowal.
"We tried our best to convince the Modi government not to pursue the Bill that goes against the constitutional provisions, besides being potentially unsafe for the indigenous people of Assam".
The TDP and Upendra Kushwaha-led Rashtriya Lok Samta Party quit the BJP-led NDA in the last one year during which the saffron party also parted ways with the PDP-headed coalition in Jammu and Kashmir.
With the Winter Session of the Lok Sabha set to end on Tuesday, it is uncertain whether the bill would be taken up for consideration in the lower house in this session.
The Bill seeks to amend the Citizenship Act of 1955 in order to grant citizenship to Hindus, Buddhists, Sikhs, Jains, Parsis and Christians from Bangladesh, Afghanistan and Pakistan if they have lived in India for six years, even if they do not possess the necessary documents.
Besides Opposition parties, Bharatiya Janata Party's allies Shiv Sena and JD (U) would also oppose the Bill in Parliament.