Following is the chronology of events in which the National Green Tribunal refused to ...

Following is the chronology of events in which the National Green Tribunal refused to lift the ban on ten-year-old diesel vehicles in Delhi-NCR:
*November 26, 2014: NGT bans all vehicles - diesel or petrol - over 15-years old from plying in Delhi-NCR.
*April 7, 2015: NGT bans 10-year old diesel vehicles.
*April 27: Government moves NGT seeking stay of its ban orders in Delhi-NCR.
*January 6, 2016: NGT expands ambit of air pollution case to metropolises like Mumbai, Kolkata and Chennai.
*July 18: NGT directs Delhi RTO to ban all diesel vehicles over 10 years old.

*July 20: Deregistration of 15 to 10 years old diesel vehicles in the national capital would be carried out in a phased manner, says NGT.

*October 7: NGT warns of halting state transport in four northern states if they do not introduce CNG.
*August 3, 2017: 'No objection certificate' would not be granted to diesel cars de-registered in Delhi-NCR for plying in other areas if the states concerned do not identify "no-pollution" zones: NGT orders.
*September 14: NGT dismisses Centre's plea seeking modification of its order banning ten-year-old diesel vehicles in Delhi-NCR.