A Federal Court judge has reserved his decision in a legal battle over the Northern Territory's container deposit scheme.
The Territory government is fighting claims by Coca-Cola Amatil, Schweppes and Lion Nathan in the Sydney court that its container deposit legislation is legally invalid.
Under the scheme, beverage makers have to pay a 10 cent refund to people who return cans and other containers to collection depots.
The drink makers argue the legislation, which came into effect last year, is invalid because of the Mutual Recognition Act.
The Act says that goods produced in one state may be sold in another without having to comply with additional requirements, including the type of material used and the way they are presented.
But the Territory's Solicitor-General argues the legislation is exempt because it applies equally to containers produced in the Territory and interstate.
Clean-Up Australia chairman Ian Kiernan is urging Territorians to boycott Coca-Cola products to protest against the legal challenge.
"They are interfering with our democratic process, and we won't put up with it," he said.
"Say no to their products," he said.
"Google Coca-Cola Amatil and see they've got huge range of products, and just say no to them.
"They'll understand that better than anything."
Mr Kiernan says some drink containers cause considerable environmental damage.
"It's breaking up; it's getting into the food chain," he said.
"It's getting in to us, with incredibly threatening results.
"We see the entanglement and the effect that beverage containers have on wildlife.
"It's just frightening."
Total Environment Centre spokesman Jeff Angel says ending the scheme will return millions of containers into the litter stream.
"The Coke case is about stopping a good environmental law because they've never liked container deposit systems," he said.
The case has been adjourned to a later date.