Academics are warning penalties in the cannabis referendum bill could have an outsize impact on underage Maori

If passed as it stands, only those over 20 would be able to use the drug.

Auckland University's Benedikt Fischer supports legalisation but says underage use penalties could have negative consequences.

He says in the worst case it could extend to targeting of minorities.

However Green Party cannabis spokesperson Chloe Swarbrick says it's a big improvement on the status quo and if passed, could be adjusted later.