Agriculture Minister Atul Bora, Water Resources Minister Keshav Mahanta and Food and Civil Supplies Minister Phanibhushan Choudhury submitted their resignations to Chief Minister Sarbananda Sonowal at the Janata Bhawan (state secretariat) here, Bora told reporters after tendering his resignation.
The strength of the BJP-led coalition ministry, led by Sonowal, has been reduced to 15, of whom 12 are from the saffron party, including the chief minister, and three BPF ministers.
"The Centre's obstinacy not to withdraw the bill forced us to take a decision to come out of the government as we cannot go against the interest of the Assamese people," Bora, who is also the AGP president, said.
The AGP is a "party formed by the blood of martyrs (shahider tez) who sacrificed their lives to protect the existence and identity of the Assam. We cannot disrespect their sacrifice by remaining in power when the Centre decided to go ahead with the bill.
"We tried our best till the last minute to convince the Centre not to go ahead with the bill but when Union Home Minister Rajnath Singh made it clear that the Centre would not budge from its obstinate stand, we decided to withdraw from the government," he said.
Bora said, "We are with the people and will join in their struggle to protect their interests at all cost."
The AGP president also thanked the people and expressed the party's gratitude for electing them in 2016 and said respecting their verdict, they had joined the government with the BJP and the BPF.
"We respect and are grateful to the people of Assam for giving us a chance to serve them," he added.
Asked what the chief minister told them about the resignation, Bora said he talked about constitutional safeguards in the bill.
Bora, however, refused to elaborate further.
Referring to the ongoing protest in the state against the bill, the AGP leader said, "We had warned both the state and Central governments that such a situation would arise, if the bill is passed."
"In the last few months, we took our movement from road to the Assembly. We met many parties -- inside and outside NDA both, such as the Nitish Kumar-led JD(U), the Shiv Sena and the Trinamool Congress. We requested them to oppose the bill. They kept our request and we are thankful to them," Mahanta said.
The Centre was adamant on their decision and they did not listen to anybody, he alleged.
Earlier in the day, the AGP executive met at the party headquarters here to discuss the resignation issue and the future course of action.
Bora told reporters after the meeting that he would announce the party's future strategy on the bill after they submit their resignation letters.
The AGP pulled out of the state government after its "last-ditch attempt to convince" the Centre to withdrew the proposed legislation failed on Monday.
The withdrawal of the AGP, which has 14 MLAs in the 126-member assembly, will not have any immediate effect on the future of the Sarbananda Sonowal-led government that still has the backing of 74 MLAs.
The BJP has 61 members and the party has support from 12 MLAs of the Bodoland People's Front and the sole Independent member.