The 2020 referendum question on recreational cannabis and possibly on euthanasia will be framed by Ministers behind closed doors.
The National Party is calling this unprecedented and undemocratic, but the Government says that Ministers will consider all advice before deciding how the question or questions will be put.
Justice Minister Andrew Little has introduced the Referendums Framework bill to provide a framework for referenda to be held in conjunction with the 2020 election.
The bill would install rules around referendum advertising similar to those used to election advertising, and would mean the question on the ballot paper would be decided by Order in Council.
Orders are made by the Ministers that make up the executive council.
National's deputy leader Paula Bennett said referendum questions should be scrutinised by all of Parliament.
"When previously has Cabinet alone decided the question of a referendum when it hasn't gone to Parliament?" she asked during Question Time today.
Government Minister Grant Robertson, answering on behalf of the Prime Minister, said he did not have that detail to hand.
"Ultimately in our system, Cabinet takes responsibility for decisions such as this. Cabinet will no doubt, as it always does, listen carefully to advice."
The bill is understood to have caused National to rethink whether it will join a cross-party group, led by Little, to oversee the cannabis referendum.
National's electoral law spokesperson Nick Smith said after Question Time that the bill was undemocratic and "an outrageous abuse of power".
He said he consulted the Parliamentary Library and there had been six referenda that followed legislation, meaning they were scrutinised by Parliament, and two that were citizens-initiated, where the Clerk of the House ensured that questions were fair.
"This bill is unprecedented, and this has never occurred in similar democracies, such as the Australian referendum on becoming a republic, or the UK's one on Brexit."
Smith said the bill would enable the Government to decide to put euthanasia to a public vote, even if a majority of MPs did not support putting the issue to a referendum.
"This exposes the transfer of power away from Parliament that the Government is giving itself.
"The conduct of elections and referenda must not be the purview of the Government of the day. It has always been subject to robust Parliamentary and public processes to ensure the election and referendum outcome are not manipulated."
Little said a bill would be drafted for the 2020 referendum about recreational cannabis, and that bill would have parliamentary scrutiny.
"There is no set procedure for setting referendum questions so Dr Smith's claim of constitutional overreach is his standard uninformed exaggeration."
MPs will vote at some stage on whether a referendum clause should be added to Act leader David Seymour's euthanasia bill, which will continue through its committee stage tomorrow.
A referendum is a condition of ongoing support from New Zealand First MPs, and without it, the vote at the third reading is expected to be on a knife edge.