The ban, as per the order on Monday, will cover vehicles in Thiruvananthapuram, Kollam, Kochi, Thrissur, Kozhikode and Kannur. The petition to revoke the order filed by Advocate ML George, Director of a legal NGO-'Fiat Justicia'.

The petitioner submitted that the tribunal had passed the order without hearing the stakeholders especially the state government and Kerala State Road Transport Corporation who are supposed to take alternative arrangements for the public transport. "The order was issued in haste and the NGT failed to consider the miseries that are to be faced by the general public due to the order," the petition said.

According to him, around 98,000 light vehicles, 42,000 heavy vehicles and 46,000 medium vehicles would have to be taken off the roads in the cities and it was reported that more than 75 per cent of the private buses operating in Kochi were more than 10 years old. Therefore, the ban order would create great hardships for the public besides affecting the movement of goods in these cities. Further, no schools buses could also be operated as most of them were more than 10 years.

The tribunal had to called for a report from the State Pollution Control Board or other competent authority on the impact of the air pollution caused by the diesel vehicles In fact, there was no justification for comparing the cities in the state with the Delhi.

He also pointed out that as per the Motor Vehicles Act, vehicles were registered for 15 years. Therefore, the tribunal could not ban plying of vehicles before the expiry of validity period of the registration. For banning 10 year old vehicles, the Act had to be amended. Besides, it was the Union Ministry of Forest and Environment which should find a solution to the air pollution after a thorough study on the issue.