By Henry Cooke

The New Zealand government will hold a referendum on personal cannabis use at the 2020 general election - and it will be binding.

Justice Minister Andrew Little announced Cabinet had made the decision on Monday on his way into caucus on Tuesday morning.

"It will be held at the 2020 general election. The agreement is that it will be binding. There is a bit of detail to still to work through," Little said.

National Leader Simon Bridges suggested that the government was attempting to distract from the general election itself, but said he didn't have a problem with the referendum being binding.

"I'm pretty cynical that you've got a government here that wants to distract from the core issues of a general election," Bridges said.

He suspected two other discussed referendums would also be included on euthanasia and electoral reform, although Little has talked down those prospects.

Bridges would be voting against cannabis legalisation and said he hadn't smoked marijuana at any point in his life.

Little said he would not be using a mooted "citizens assembly" for policy development, something the Green Party had pushed for.

The Green Party negotiated the referendum during 'confidence and supply' talks to form the government.