The Supreme Court on Monday said that in order to combat the deteriorating air quality level in Delhi, it is contemplating passing an order to ensure that the Graded Response Action Plan IV (GRAP IV) is in force even if the air quality index (AQI) improves and goes below 300.

GRAP IV is usually implemented when AQI exceeds 450 and it involves complete ban on construction activities, school closure and odd-even scheme for vehicles.

"We are making it very clear that you will not go below stage 4 without our permission now even if AQI goes below 300. That is the order we are proposing," the Bench of Justice AS Oka and AG Masih said.

It then posted the case for further consideration later today.

The Bench was hearing a plea seeking enforcement of measures to improve ‘severe’ Air Quality Index.

The GRAP IV is currently in force in the national capital after the Commission for Air Quality Management (CAQM) activated the same in response to the worsening AQI.

As per GRAP IV, entry of trucks into Delhi, except for trucks carrying essential commodities/providing essential services, would be banned.

All LNG/CNG /Electric/BS-VI Diesel trucks shall however be permitted to enter Delhi.

GRAP IV will also mean light commercial vehicles registered outside Delhi, other than EVs/CNG/BS-VI diesel, can't enter Delhi except those carrying essential commodities/ providing essential services.