Nations have agreed that the world needs to completely stop plastic waste from entering the oceans.
The UN resolution, which is set to be sealed tomorrow, has no timetable and is not legally binding.
But ministers at an environment summit in Kenya believe it will set the course for much tougher policies and send a clear signal to business.
A stronger motion was rejected after the US would not agree to any specific, internationally agreed goals.
Under the proposal, governments would establish an international taskforce to advise on combating what the UN’s oceans chief has described as a planetary crisis.
Environmentalists say ministers are starting to take plastic waste more seriously, but need to move much more quickly.
Li Lin from the green group WWF said: “At last we are seeing some action on this issue, but we still don’t have the urgency we need. The problem needs solving right now.”
One contentious issue is the wish of delegates to include businesses on the global taskforce.
Ministers say the problem will not be solved without business, but green groups point out that some firms in the plastics industry have been lobbying against restrictions for decades.
Vidar Helgesen, Norway’s environment minister, a leading voice in the talks, said: “Business is listening to markets and seeing how marine litter is a growing popular concern.
“It’s possibly the fastest-growing environmental problem and it’s therefore a fast-growing problem for business.
“We need to bring on board those companies that want to change things, then look at taxes and regulations to make more companies act sustainably.
“We also need to mobilise businesses like aquaculture that suffer from marine pollution.”