Lawyer Harish Salve, who is assisting the apex court in air pollution cases as an amicus curiae or friend of the court, pointed out that the jurisdiction of the tribunal to pass such an order was questionable as the case was before the Supreme Court.

“Since the NGT has passed the order, it is desirable to look at it first. We may add something more to their order or modify that order,” chief justice of India H.L. Dattu told Salve.

Incidentally, the Supreme Court had, on Monday, asked the Delhi government to respond in a case seeking imposition of a pollution charge.

The case will come up for hearing on 9 October.

The Delhi government, represented by lawyer Dushyant Dave, told the court that it was in favour of imposing a pollution compensatory charge.

Salve, solicitor general Ranjit Kumar and Dave are required to give suggestions to the court about implementation of the pollution compensatory charge.

The propriety of the tribunal passing an order on a matter before the apex court is a non-issue, according to Alok Prasanna Kumar, working with Vidhi Centre for Legal Policy, a think tank.

“While I don’t know the specific time line to this case—as to when the application was filed before the apex court or the NGT—for any case which comes to the Supreme Court, unless it stays all other proceedings before other courts, lower courts are free to pass any order,” he said.

The NGT, on 7 October, issued an order directing payment of an “environment charge” by trucks entering Delhi.

Salve filed an application before the Supreme Court earlier this month, saying that nearly 39,000 trucks entered the city every day, causing heavy pollution. He had asked the court to direct payment of a pollution compensatory charge.