Elections are a time for audacious promises – and in this, the Bharatiya Janata Party’s campaign pitch to implement the National Register of Citizens all across the country is one of the brashest in the history of modern India.

The National Register of Citizens is an exercise currently underway in the state of Assam that seeks to prepare a list of genuine Indian citizens by identifying undocumented migrants.

The BJP first hinted at a National Register of Citizens for all of India in its manifesto released on April 8 when it proposed to “implement the NRC in a phased manner in other parts of the country”. On April 11, BJP President Amit Shah made it clear at a campaign rally that the National Register of Citizens would be used to remove “infiltrators” – unless they were Hindu or Buddhist. He repeated this promise on Monday.

The BJP’s focus on a communal National Register of Citizens is not out of step with other elements of its election campaign, which has placed a great deal of emphasis on issues of identity. This has included support for lynchings, attacking parties that have the support of minority communities and nominating a terror-accused as a parliamentary candidate.

However, even benchmarked against these examples, the use of the National Register of Citizens is worrying.

For one, it seeks to fundamentally alter the secular nature of the Indian Constitution by making the concept of citizenship one that is explicitly based on religious identity. Associated with the Register is the Citizenship Amendment Bill, which the party has championed. The legislation, which lapsed in the Rajya Sabha in Februrary, proposed to ease citizenship criteria for non-Muslim refugees who had fled religious persecution in Bangladesh, Pakistan and Afghanistan. However, given that the most alarming instance of religious persecution today is that of the Muslim Rohingyas in Myanmar – a country that shares a border with India – this explanation is a flimsy one.

Not only does the National Register of Citizens go against the Indian Constitution’s bar on discriminating between people based on their faith, it would be a practical nightmare. The example of Assam is clear to see. Scroll.in’s Ipsita Chakravarty, who has reported extensively on the National Register of Citizens, described it as a “whimsical bureaucratic process”.

The procedure was convoluted, requiring residents to provide extensive documentation in a region with widespread poverty and low literacy. In effect, Assam’s National Register of Citizens penalised poverty as much as migration. The result was 40 lakh individuals – both Hindu and Muslim – being left out of the draft National Register of Citizens, which was released in 2018. Even now, the final outcome of the National Register of Citizens is unclear as are India’s plans for what to do with such a potentially large stateless population.

As intractable as Assam’s problems are, it is a fairly small state. India’s population is 43 times that of Assam. The country has more than 170 million Muslims – a number that by itself would be the world’s seventh most-populous country. A process to check the citizenship of such a large body of people is unprecedented globally. To undertake a communal National Register of Citizens targeted at Muslims would not only contravene the secular nature of India, it would threaten the country’s stability.