Associate Health Minister Peter Dunne conceded that the latest move to declare two substances used in K2 illegal was something of a cat and mouse game for authorities, as others were brought into use.
"[That's] until we can deliver the killer punch in August when the Psychoactive Substances Bill will become law."
But the latest moves were a solid start, Mr Dunne said.
Last Tuesday Mr Dunne announced a Temporary Class Drug Notice banning the two substances found in tested samples of the synthetic cannabis. The ban comes into effect on Thursday and brings to 35 the number of substances banned under temporary notices - more than 50 products containing those substances are now off the market.
Submissions on the planned legislation closed on Wednesday and the Health Select Committee is due to report the Bill back to Parliament in mid-June.
"What this ban will do in the meantime is force more of the K2 product off the shelves and that is the best outcome we can have at this point with a product that is clearly bad for people."
Mr Dunne said the industry and the outlets that sold it had "no integrity whatsoever".
"There is no goodwill and there is no decency in this industry, and that is why we are legislating. They prove day-in and day-out that they cannot be trusted.
"Again, we are hitting some of the K2 product because it appears to be at the forefront of harm to young people. We have tested the products and we will test more, but I am counting the weeks until the law that will reverse the onus of proof on safety comes in."
The two K2 substances being banned are BB-22 and 5F-AKB48, and from next Thursday it will be illegal to import, manufacture, sell or supply the substances, with penalties of up to 8 years imprisonment.
"The Health Ministry considers that these particular substances pose a risk at least comparable to other already banned synthetic cannabis substances, therefore I have made the decision that it needs to be banned," Mr Dunne said.
He endorsed police enforcement of the bans and also encouraged community pressure on dairies and other outlets that sold the products.
"We need to apply pressure from all ends on a dirty industry until we can get our world-leading legislation in place."