Come June 5 (environment day), the owners or drivers of diesel vehicles will have to produce a valid “pollution under control” certificate at petrol pumps for a refill.

The state environment department has decided on the move to ensure that diesel vehicles — a major source of air pollution — renew their certificate every six months.

“Judging by how the scheme works out, we will consider extending the order to petrol vehicles, too,” said environment secretary M.L. Meena.

“The transport minister has approved the proposal and we will soon issue a notification under the Air (Prevention & Control) Act, 1981. It will be enforced from the next environment day,” Meena added.

“The order will be circulated among all petrol pumps. A team comprising representatives of police, transport department and the state pollution control board will monitor the implementation,” said Biswajit Mukherjee, the senior law officer in the environment department.

The move was recommended in 2000 by a panel appointed by the high court to suggest ways to curb air pollution.

Hardly 20 per cent of the vehicles in the city have a valid “pollution under control” certificate. The compliance rate is even poorer in the diesel segment. “The demand for the certificate is so low that many auto emission testing centres want to shut down,” said Asim Banerjee, of the auto emission testing centres association.