New Delhi’s air is often bad at this time of year. In addition to crop burning, the smog worsens as people set off firecrackers to celebrate Diwali, the Hindu festival of lights.

Taking cars off the roads

Even before the heavy smog, the city’s government signaled that it would implement the odd-even car rule this month for the first time since 2016, meaning more than 4 million cars could be taken off the road each day. Anyone who breaks the rules faces a 4,000 rupee ($56) fine.

But not everyone has to follow the rules. Senior leaders in the government, cars carrying children wearing school uniform, cars with only female passengers, and police vehicles are exempt.

New Delhi is home to more than 8.8 million registered motor vehicles, more than any other Indian city, according to government figures from 2016.

And those cars appear to be a big part of the problem. A 2006 study — which was quoted by an official government report released in 2016 — found that cars contributed to 72% of New Delhi’s pollution. The government hasn’t released more recent figures.

With elections coming up next year, some opposition party politicians have accused the local government of trying to score points with voters.

Tajinder Pal Singh Bagga, the spokesman from the New Delhi arm of Indian Prime Minister Narendra Modi’s Bharatiya Janata Party, said the odd-even rule had already been tried — and it didn’t help. “This is totally for the elections,” Bagga told CNN. “If they had found a permanent solution, then all this would not be needed.”

But Saurabh Bhardwaj, the chief spokesman for the ruling Aam Aadmi Party in the city, said the party had done other things to stamp out the smog, including closing thermal power plants. Although there had been some public push back to the odd-even rule, Bhardwaj said it wouldn’t change the party’s stance.

“For pollution, we are ready to take that risk (to our popularity).”