In New Delhi, Prime Minister Narendra Modi on Monday criticized Congress for imposing a state of emergency in 1975, calling it a "black spot" on democracy when the Constitution was "discarded."

It brought back memories of the 21-month period when then Prime Minister Indira Gandhi ordered a crackdown on civil liberties.

Gandhi made the announcement of the imposition of the state of emergency in a late-night All India Radio broadcast on June 25, 1975, shortly after the Supreme Court granted a conditional stay of the Allahabad High Court verdict that declared his election to the Lok Sabha null and void. . The apex court asked Gandhi to stay away from parliamentary proceedings.

"The President has proclaimed an Emergency. There is nothing to be frightened of. I am sure that you are all aware of the deep and widespread conspiracy that has been brewing since I began to introduce certain progressive measures for the benefit of the common man and woman in India," Gandhi said in his midnight address to the nation that triggered a series of arrests of opposition leaders.

Gandhi had won the 1971 Lok Sabha elections by a landslide, winning 352 seats in the then 521-member Parliament. His star was on the rise after he had dealt a mortal blow to Pakistan by liberating Bangladesh in December 1971.

However, India was also mired in instability with the Navnirman students' agitation in Gujarat, the Jayaprakash Narayan (JP) movement in Bihar, the railway strike led by George Fernandes in 1974, the Allahabad High Court judgment of June 12, 1975 which declared the Lok Sabha election from Rae Bareli as null and void.

The Congress's loss in the Gujarat elections to a five-party coalition and the opposition rally at Ram Lila Grounds in Delhi on June 26, 1975 further put Gandhi in the hot seat and was seen as a trigger for the imposition of the state of emergency.

JP also called for a nationwide movement to remove Gandhi as prime minister amid calls from many within the Congress for his removal.

Opposition leaders JP, L K Advani, Atal Bihari Vajpayee and Morarji Desai and dozens of activists were jailed soon after the Emergency was imposed.

The 21-month period was also known for excesses such as forced mass sterilizations, press censorship, suspension of constitutional rights, and centralization of power.

According to Article 352, the President can proclaim an emergency if there is a serious threat to the security of the country, whether due to war, external aggression or armed rebellion.

Before June 1975, then Prime Minister Jawaharlal Nehru declared a state of emergency between October 1962 and January 1968 during the India-China War.

The second emergency was declared by Gandhi on December 3, 1971 due to the war between India and Pakistan that led to the creation of Bangladesh.