The Supreme Court on Monday slammed the Delhi government over the delay in the implementation of stage 4 of the Graded Response Action Plan (GRAP) in the national capital despite the alarming rise in pollution. 

The air pollution level dropped into the "severe-plus" category, with the overall Air Quality Index (AQI) reaching 481, marking the highest air pollution level of the season so far on Monday morning. "The moment it reaches 300 to 400 GRAP has to be invoked. How can you take risk in such matters of delaying applicability of GRAP?" the court asked. 

The apex court asked the Delhi government about steps taken to curb the rising pollution levels in the national capital. "Will not allow scaling down of preventive measures under stage 4 of GRAP even if AQI goes below 450," the court said.