He said rolling out vehicular restrictions within a short notice period would be challenging but the government would abide by the guidelines approved by the Supreme Court.

"Odd-even will have to brought in as per levels of pollution. If it crosses a certain level we will enforce it. We had requested the Centre that the Delhi government will need at least seven days in this regard.

"But the notification demands that the measure be imposed within two days. The thing is government can do it but the challenge would be sensiting the masses as lakhs of vehicles will go off roads," he told reporters.

Under the plan, odd-even road rationing scheme and halt on construction activities may be imposed across Delhi-NCR if air quality remains at the "emergency" level for 48 hours.

Importantly, unlike the two rounds of the scheme implemented last year, any such future action under the graded plan when pollution touches 'emergency' level may also have two-wheelers under its ambit.

Terming air pollution in Delhi and NCR as a "matter of serious concern", the Environment Ministry has empowered the Environment Pollution (Prevention and Control) Authority (EPCA) under the Environment (Protection) Act, 1986 to implement the plan.