Congress leader Rahul Gandhi on Tuesday criticised the Narendra Modi-led government for pushing the Citizenship Amendment Bill through the Lok Sabha the day before, calling it “an attack on the Indian Constitution”. The proposed amendments to the 1955 Citizenship Act were approved in a 311-80 vote after more than seven hours of heated debate.

“Anyone who supports it is attacking and attempting to destroy the foundation of our nation,” Gandhi tweeted.

If enacted, the amended law will grant citizenship to persecuted Hindus, Buddhists, Sikhs, Jains, Parsis and Christians from the Muslim-majority nations of Bangladesh, Afghanistan and Pakistan, provided they have resided in India for six years. The cut-off date is December 31, 2014.

The Bill’s critics are against using religion as the basis of providing citizenship, and ask why Muslims were left out. They have also questioned why other neighbouring countries such as Nepal, Myanmar and Sri Lanka were left out of the ambit of the law. During the discussion in the Lower House, a number of Opposition leaders said the bill was unconstitutional. Hyderabad MP Asaduddin Owaisi compared it to Nazi Germany’s race laws, and tore up his copy of the Bill at the end of his speech.

Congress General Secretary Priyanka Gandhi Vadra on Tuesday said “India’s tryst with bigotry and narrow minded exclusion” was now confirmed. “Our forefathers gave their lifeblood for our freedom,” she tweeted. “In that freedom, is enshrined the right to equality, and the right to freedom of religion. Our Constitution, our citizenship, our dreams of a strong and unified India belong to all of us.”

The Congress leader vowed to fight against the Bharatiya Janata Party government’s agenda to “systematically destroy our Constitution and undo the fundamental premise on which our country was built with all our might”.

Senior Congress leader and former Union Finance Minister P Chidambaram also castigated the government. “CAB is unconstitutional,” he tweeted. “Parliament passes a bill that is patently unconstitutional and the battle ground shifts to the Supreme Court. Elected parliamentarians are abdicating their responsibilities in favour of lawyers and judges.”

Out on bail last week after spending 106 days in Tihar Jail in connection with the INX Media case, Chidambaram said defeats such this were “the price we pay for giving a party a brute majority”. He accused the BJP of “trampling over the wishes of the state and the people”.

The Bill is likely to be tabled in Rajya Sabha on Wednesday afternoon.

On Monday, Union Home Minister Amit Shah blamed the Congress for Partition, and said the amendments would not have been needed had India not been divided on religious lines. The home minister rejected allegations that the bill was anti-Muslim, and claimed it had the endorsement of 130 crore citizens. “We will have to differentiate between intruders and refugees,” he said, adding that the bill was not even “0.001% against India’s minorities”.

Also read: An uneasy silence among Indian Muslims marks the passage of the Citizenship Amendment Bill