While the ban was widely welcomed, the Indonesian Plastic Recyclers Association filed a legal challenge in March with the Supreme Court, arguing the policy would harm manufacturers and recyclers of single-use plastics, as well as the trash pickers who make a living from scavenging plastic waste. The association branded the ban discriminatory and a violation of human rights.

But in its ruling on May 23, which was only published July 9, the Supreme Court rejected the challenge. It said the ban, which came into effect on July 2, did not violate Indonesian laws.

Environmentalists have welcomed the ruling, calling it a positive precedent for other local governments dealing with a plastic waste problem and considering issuing their own bans on single-use plastics.

“This decision provides significant legal support for efforts to reduce plastic waste in Indonesia,” said Andri Gunawan Wibisana, a lecturer in environmental law at the University of Indonesia.

Bali generates 1.6 million tonnes of waste a year, nearly a fifth of which is plastic, according to recent research by the provincial government. Some 33,000 tonnes of plastic ends up in the island’s waterways and seas every year.

I’m calling on other regional governments to implement a similar policy so Indonesia can be free from single-use plastic waste.

I Wayan Koster, governor, Bali, Indonesia

In justifying the ban, Balinese authorities say that plastic bags, straws and Styrofoam can’t be recycled in an economically feasible way, and that trash pickers typically don’t even collect these kinds of plastics to sell to recycling facilities.

“I’m calling on other regional governments to implement a similar policy so Indonesia can be free from single-use plastic waste,” said Bali Governor I Wayan Koster. He has also pledged to expand the policy to include banning a wider range of polluting materials.

Indonesia is the number two source of the plastic waste that ends up in the ocean, behind only China, and has set itself the target of reducing that waste output by 70 per cent by 2025.

The court ruling comes amid a growing resistance to plastic waste in Indonesia and across Southeast Asia. Indonesia is among the countries in the region that recently sent back cargo containers of plastic household waste from the U.S., Canada and Europe. Malaysia and the Philippines have done likewise.

Member states of the Association of Southeast Asian Nations (ASEAN), including some of the biggest producers of the plastic waste in the oceans, have declared their commitment to addressing the trash crisis.

Environmentalists have welcomed the ASEAN declaration, but there are worries that implementation will be a challenge, because the group has a code of non-interference that would leave necessary policymaking in the hands of individual member countries.