Three of the five judges hearing the case said it is unconstitutional; the other two wanted it banned for six months till the government introduces new legislation. The majority opinion held that triple talaq "is not integral to religious practice and violates constitutional morality".

The judges in favour of a new law wanted the government to take into account the concerns of some Muslim organisations who are critical of any attempts to meddle with religious laws, arguing it curtails their constitutional right to govern their affairs.

The All India Muslim Personal Law Board (AIMPLB), a non-governmental body which oversees the application of Muslim personal law, opposes any ban on triple talaq and argues this is a religious matter and not for the courts.

The Supreme Court referred to the fact that several Islamic countries like Pakistan do not allow triple talaq; judges questioned why it should not be abolished in India.

The Supreme Court has for the first time reviewed whether triple talaq is fundamental to Islam and therefore legally binding. Three of the five judges held that triple talaq violates the tenets of the Quran.

Critics say it leaves women destitute and robs them of basic rights. "We told the court that the practice has no basis in the law or in the Koran," said Balaji Srinivasan, a lawyer for Shayara Bano whose husband split from her by writing "talaq" three times on a piece of paper.

The verdict was delivered by a panel of five judges from different major faiths - Hinduism, Christianity, Islam, Sikhism and Zoroastrianism. Arguments concluded in May.

India allows religious institutions to govern matters of personal law - marriage, divorce and property inheritance - through civil codes; so far, triple talaq has been considered a legal avenue for the country's nearly 180 million Muslims to end marriages.

But Prime Minister Narendra Modi's government has backed the petitioners in this landmark case, declaring triple talaq unconstitutional, and derogatory and discriminatory for women. "Judgment of the Hon'ble SC on Triple Talaq is historic. It grants equality to Muslim women and is a powerful measure for women empowerment," PM Modi tweeted today.