The government will announce today the form of next year's cannabis referendum, but won't be revealing who leaked a Cabinet paper on the poll options to the National party.
National's drug reform spokesperson Paula Bennett was leaked a Cabinet paper discussing the four options for the cannabis referendum.
It said there were four options: one which would see a law already in place ahead of the election be triggered by a yes vote, while other three would not be binding as the government would not be obliged to act on them.
Prime Minister Jacinda Ardern said she considered the leak to be serious, but did not believe any Cabinet ministers were involved, and she did not intend to investigate.
'This is really the first example of this' - Jacinda Ardern
She said the circulation of cabinet papers can be reasonably significant and it wasn't worth the time or effort when an investigation might not provide any answers.
"I trust my cabinet. I have good relationships... by and large we do pretty well."
She said she was almost certain an investigation would not be able to determine who was involved in the leak.
Justice Minister Andrew Little will today announce the details for the referendum, which will take place at the same time as the general election next year.