Anti-noise activists have slammed the state government’s decision to allow housing societies to use traditional instruments minus loudspeakers till midnight on all nine days of the Navratri festival.

“Under which law can the government allow this to happen? It is illegal and in direct contempt of the Supreme Court (SC) ruling that has banned loudspeakers and instruments after 10pm,” said Sumaira Abdulali, convener, Awaaz Foundation.

According to Abdulali, the decision cannot be challenged in court in the absence of a government notification. “We are absolutely prepared to move the Bombay high court. However, it will be very difficult for the government to come out with a notification because it would mean a deliberate attempt to violate SC orders.”

On Monday, activist Sudhir Badami wrote to Chief Justice Mohit Shah asking him to reprimand the state political leadership, environment secretary and police commissioner for allowing people to violate noise rules without taking any action against the offenders.

“My email seeks that the Chief Justice convert it into a suo motu public interest litigation (PIL) and expeditiously direct the government according to the prayer,” said Badami.

For the first time this year, the government allowed the use of traditional instruments during the 11-day Ganesh festival. The sound of these instruments amplified on a loudspeaker resulted in soaring sound levels on the fifth day and eleventh day of Ganesh immersions.

“The government is violating the spirit of the (noise) Act. We will consider approaching the national green tribunal against the use of traditional instruments till midnight, since the noise rules make it clear that no instrument can be used post 10pm,” said AM Marathe, anti-noise activist from Navi Mumbai.