Mega referendum: Kiwis could vote on euthanasia and cannabis at the same time

New Zealanders could be voting in a bumper referendum on cannabis and euthanasia by the end of next year.

The Green Party was promised a referendum on legalising the personal use of cannabis at or by the 2020 election and there's a second possible referendum looming on the horizon - on legalising euthanasia.

New Zealand First said it would support the voluntary euthanasia Bill currently before Parliament if a conscience vote allowing a binding referendum on the law could be held.

Justice Minister Andrew Little said if the referendum goes ahead, it could make sense to combine the two referenda.

"If you're gonna do one, you might as well do a job lot," he explained. "It would make sense to not have to spend a lot of money on a succession of referenda."

There's no decision yet on when the referendum on cannabis will be held.

"Cabinet just hasn't got around to considering the details of it," Mr Little told Newshub.

"Obviously, when we consider a date for it, we need to weigh up [whether] we run it at the same time as the general election - there would be some cost saving with that - or the other question is, do we want the general election dominated by the referendum?"

The Greens have different preferences on when the cannabis referendum should be held.

Green Party leader James Shaw would prefer to hold the referendum at the same time as the election.

"People are going to be going to the polling booths anyway," Mr Shaw said.

"Mail is a declining way of staying in touch in this country, so I don't know what the effect of turn-out on a postal referendum would be."

As to whether the referendum could end up dominating the election period, Mr Shaw said "there are ways you can stay out of the politics of it."

Greens spokesperson of drug law reform Chloe Swarbrick said if it's held in 2019, that could avoid politicising the issue.

"If we hold it in 2019, it may not be deeply politicised, polarised or pigeon-holed - and we are hopefully able to have more of an evidentiary discussion.

"If we hold it in 2020 we might end up with something where it dominates the issues and we don't end up talking about things like housing, criminal justice or healthcare."

Newshub.