The Green Party is defending its MP Nandor Tanczos over products being sold in a store he part owns.
The so-called legal highs, Exodus and Frenzy, are sold through the Hemp Store in Auckland.
The store promotes the products, which are sold in capsule form, as herbal highs and restricts their sale to adults aged 18 and over.
Exodus and frenzy are not illegal. But they have come under the spotlight after chemicals they contain were scheduled by the United States Drug Enforcement Agency under the US Controlled Substances Act.
The agency's website says chemicals such as Benzylpiperazine, an active ingredient in both products, produce stimulant and hallucinogenic effects similar to ecstasy and tablets containing them are increasingly appearing on the club scene.
The website says at high doses these chemicals produce hallucinations and convulsions.
The Drug Foundation's executive director Sally Jackman says new products are appearing fairly regularly as substitutes for substances that are banned.
The Health Ministry says it is monitoring overseas literature but at this stage there is not sufficient reason to move to have the substances classified under the Misuse of Drugs Act.
But opposition MPs say even though exodus and frenzy are not illegal, it is unacceptable for an MP to be making profit out of such products. National's leader Bill English says Tanzcos should either withdraw them from his store or get out of the business.
English says such products, even if legal, are too close to the fringe of the illicit party drugs scene.
Tanczos is rejecting such criticism. He describes the herbal highs as energy supplements and compares them to the caffeine energy drink V or a decent coffee.
And he is playing down talk of their use as substitutes for party drugs such as ecstasy or speed.
Tanczos says the Hemp Store voluntarily restricts the sale of the products to adults and says they are sold at shops all over the country.
Tanzcos says he was unaware until recently of the US Drug Enforcement Agency action, but says no concerns have been raised by the Health Ministry in New Zealand.
Greens' co-leader Jeanette Fitzsimons is defending her MP and says she is not concerned that the criticism could do damage to the party.
Fitzsimons says she expects that if any of the products sold in the Hemp Store were to be made illegal it would stop selling them.
