The Federal Court in Sydney has begun hearing a legal challenge against the Northern Territory container deposit scheme.
The Territory government is fighting claims by Coca-Cola Amatil, Schweppes and Lion Nathan 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.
"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."