The government is set to move court on Friday seeking a combined deadline to phase out the two-stroke autos that should have gone by December 31 and replace all old commercial vehicles that are supposed to go by March 31.

“We intend suggesting July 31 as the combined deadline for these tasks,” said a source in Writers’ Buildings.

Home secretary Ardhendu Sen confirmed that the government would seek more time but refused to say whether it had July 31 in mind as the cut-off date.

“A revised timeframe will be submitted to the court along with the status report on what we have done to carry out the order to ban polluting autos. We have followed the court’s order,” Sen said at Writers’ Buildings.

Following the court’s order for the Bengal government of course means seizing only 90 two-stroke autos out of 67,000 till Thursday evening.

Green activist Subhas Dutta, whose clean-air petition had led the court to ban two-stroke autos, insisted that the government should come up with a roadmap for implementation of the order.

“It can’t ask for a new deadline without saying how it intends to fulfil its obligations. The administration must also submit action-taken reports to the court at regular intervals,” Dutta said.

Environment department officials said 3,000 autos would either be replaced or made LPG-compliant every month, depending on whether they are two-stroke or four-stroke.

The deadline for conversion of four-stroke petrol autos is March 31. All commercial vehicles that are 15 years old or more must also be replaced by that date, according to the court’s order on July 18 last year.

Dutta said he would recommend a panel on the lines of the Bhure Lal Committee — appointed by the Supreme Court to monitor the implementation of steps to reduce vehicular pollution in major cities — to keep the government on its toes.

“This committee should also probe what the transport department did in the five-and-a-half months between the court issuing the order and the deadline to phase out two-stroke autos.”

Chief secretary Asok Mohan Chakrabarti went into a huddle with the home secretary, environment secretary M.L. Meena and transport secretary Sumantra Chowdhury on Thursday to frame the government’s response to the questions that could be asked in court on Friday.

The chief secretary also spoke to advocate-general Balai Ray, who will represent the government in court along with senior counsel Alok Ghosh and Sandip Srimani.

Chief minister Buddhadeb Bhattacharjee, who is in Cochin, has been “briefed” about the government’s plans.