India’s interior minister has vowed to further implement a contentious common civil code for states governed by the ruling Hindu nationalist party, a move expected to stoke concern among minority Muslims.

India’s 1.4 billion people are subject to a common criminal law, but rules on personal matters such as marriage, divorce and inheritance vary based on the customary traditions of different communities and faiths.

The introduction of a Uniform Civil Code (UCC) to replace those diverse rules has been a long-standing goal of Prime Minister Narendra Modi’s ruling Bharatiya Janata Party (BJP).

At least four states have implemented the UCC so far.

“We have introduced the UCC in several states … I am confident that we will implement (it) in all 21 states governed by the BJP-led National Democratic Alliance by 2029,” Home Minister Amit Shah said on Sunday.

The campaign for a standardised civil code has raised concerns, especially among Muslim citizens, who say such a move would infringe on their religious freedoms.

Supporters say the UCC gives Muslim women the same rights as others by ending polygamy, setting equal property inheritance rights for sons and daughters, and requiring divorce processes to take place before a civil court.

India, the world’s most populous country, is majority Hindu. It is also home to an estimated 220 million Muslims, giving it the world’s third-largest Muslim population.

India’s next national elections are due in 2029, after Modi won a third successive term in 2024, when he was forced into a coalition government.