The Asom Gana Parishad, an alliance partner of the ruling Bharatiya Janata Party in Assam, on Monday threatened to break ties if Parliament passes the “obnoxious” Citizenship (Amendment) Bill, 2016, during the Winter Session starting on Tuesday, PTI reported.

Party President Atul Bora has written to BJP National President Amit Shah asking him to intervene in the matter. Bora said that if Parliament passes the bill, the Asom Gana Parishad will have no option but to “repudiate the existing alliance”. The letter, which Bora showed reporters in Guwahati on Monday, says that the “provisions of Assam Accord and the ongoing preparation of the National Register of Citizens will be totally frustrated and the Assamese language, culture, and demography will be changed” if the bill is passed.

Bora, along with party working president Kesab Mahanta and leader Phani Bhusan Choudhury are ministers in the Sarbananda Sonowal-led government.

“It is pertinent to mention herein that the Asom Gana Parishad is fully committed to the implementation of the provisions of the [1985] Assam Accord and hence, we can never support the obnoxious Citizenship [Amendment] Bill, 2016,” the letter said. It reminded the BJP that the Asom Gana Parishad had entered into an alliance with it “on the basis of clear understanding of the Assam Accord and other major issues of Assam, including the seat adjustments”.

The letter claimed that instead, the Centre “violated” the understanding between the two parties, and was trying to make the Assam Accord “meaningless”.

The bill, which was introduced in the Lok Sabha in July 2016, aims to make crucial changes to the Citizenship Act of 1955. If passed, it would make undocumented immigrants – Hindus, Christians, Buddhists, Sikhs, Jains and Parsis – from Afghanistan, Pakistan and Bangladesh eligible for citizenship. It would also ease the terms for naturalisation of individuals from these groups. Several groups in Assam have objected to the proposed amendments.

Reacting to the Asom Gana Parishad’s letter, BJP state chief Ranjeet Kumar Dass said the matter of the alliance will be discussed at the saffron party’s National Executive meet on December 13.

The Asom Gana Parishad had threatened to pull out of the alliance earlier this year too. In October, BJP spokesperson Rajdeep Roy said the Asom Gana Parishad could break ties with his party if it wished to.