National's deputy leader Paula Bennett has pulled a stunt at Parliament, brandishing a bag of 'look-a-like cannabis' to demonstrate how much a person could buy every day under the proposed legal regime.

The government on Tuesday unveiled the rules which would govern a recreational cannabis market if the public gives it the go-ahead in next year's referendum.

Among the restrictions is a purchase limit of 14 grams per day - roughly half an ounce.

Mrs Bennett says that is way too much and took a 14 gram bag of oregano into Parliament to prove it.