They don't pay any heed to the interests of the operators,' said Sadhan Das of Joint Council of Bus Syndicate.

The Calcutta High Court issued an order in July last year to ban commercial vehicles registered before Jan 1, 1993 from Kolkata and its outskirts. It said the order should be implemented by Dec 31, 2008, in the KMA, which includes parts of north and south 24-Parganas, Howrah and Hooghly districts.

Later, the ban was extended till July 31, 2009 following a plea by the state government.

The court also directed that all auto-rickshaws, irrespective of their date of registration, would have to convert to either compressed natural gas (CNG) or liquefied petroleum gas (LPG).

Chowdhury said the government would have to phase out 6,000 taxis, 3,000 buses and 35,000 autos by July 31.

Last Friday, a division bench of Calcutta High Court comprising Chief Justice S.S. Nijjar and Justice B. Somadder had said that it would not entertain any request from the state government to extend the July 31 deadline for phasing out old commercial vehicles.

State advocate-general Balai Roy submitted that the transport department was 'determined' to phase out old vehicles and is holding talks with the owners on a regular basis.

Earlier, the state's main opposition Trinamool Congress opposed the government's decision to ban old commercial vehicles from the city streets overnight. They have threatened to call a shutdown if the government takes such stringent action without giving adequate time to the operators.

Reacting to the order, a group of agitated auto-rickshaw drivers also went on a rampage and set a bus on fire on a busy south Kolkata street.

Blaming the state government, Trinamool chief Mamata Banerjee said there were around 300,000 people in Kolkata who would be directly affected if the state government implemented the ban 'in such a short span'.