The National Green Tribunal on Tuesday granted the chief secretaries of eight states a three week extension to submit reports on the number of registered diesel and petrol vehicles in its most polluted cities.

The tribunal was hearing a petition to extend its ban on diesel vehicles to cities apart from Delhi. The states include Bihar, Karnataka, Maharashtra, Punjab, Tamil Nadu, Telangana, Uttar Pradesh and West Bengal. A day earlier, the tribunal had castigated the states for the shoddy reports they had submitted and threatened to issue bailable warrants to all eight secretaries if they did not comply and file reports.

The reports the states had submitted, Justice Swatanter Kumar, who is also chairperson of the tribunal, noted, were incomplete and misleading.

“According to your report, Mumbai has a population of 11 lakhs,” he said, as reported by The New Indian Express. “This is the joke of the first category.”

This is not the first time the tribunal has threatened secretaries with arrest. Last May, it issued a warrant with a bail amount of Rs 10,000 against Delhi’s chief secretary, for failing to appear in a case relating to the closure of steel pickling industries in Wazirpur. In November, it threatened to do the same for Chhatisgarh’s chief secretary for not filing a compliance report on the bursting of crackers and in January, for the Telangana chief secretary for not appearing in a case of land grabbing.

In an unrelated case, the tribunal on May 23 ordered a ban on diesel vehicles older than ten years in six cities in Kerala and a temporary stay on registration of new diesel vehicles of more than 2000 cc, on an appeal from the Lawyers Environmental Awareness Forum, a group of Kerala high court advocates.

Tangle of cases

It might seem as if everyone from the National Green Tribunal to the Kerala High Court to the Supreme Court has been making different rulings on diesel vehicles for the last year, but some of these cases are related. Both the tribunal and apex court cases have been filed by Sanjay Kulshrestha, a paediatric surgeon from Agra.

He filed the first case with the tribunal to ban diesel vehicles in 2014, after noticing several cases of miscarriages that he attributed to a rise in pollution.

When the tribunal ordered a ban on registering any diesel vehicle in Delhi in April 2015, vehicle manufacturers appealed to the Supreme Court. The apex court in turn narrowed the ban to apply only to luxury sports utility vehicles and cars with engine capacities of more than 2000 cubic centimetres towards the end of December. This affects 63 car models manufactured by 17 companies. The ban does not apply to commercial vehicles such as trucks.

In February, Kulshrestha impleaded himself into an ongoing case in the Supreme Court to petition it to extend the ban to small and mid-sized vehicles as well and in March, the Supreme Court extended the ban yet again, until manufacturers agreed to charge a one-time pollution cess. This case is still being heard.

The government has responded on the side of vehicle manufacturing industries so far. On May 30, defence minister Manohar Parrikar, while inaugurating a garbage and sewage treatment facility in Panaji, Goa, criticised the court for issuing “senseless” and “unscientific” orders while referring to the diesel ban in Delhi.

“How is a defence minister getting involved in this case?” Kulshrestha asked. “If anyone, it should be Prakash Javadekar, the environment minister. If you are not taking care of the environment, at least don’t interfere if someone else is doing it.”

As this case was unfurling in the apex court, the tribunal recused itself from hearing any further petitions related to Delhi in December. Kulshrestha then appealed to the tribunal to extend the ban to other states, which is how the chief secretaries are now involved.