Opposition parties say the Government has picked the worst possible time to hold a non-binding referendum on the partial asset-sales programme.
Voting will open on Friday, 22 November and close three weeks later, on Friday, 13 December.
The referendum will ask whether voters support the Government's sale of up to 49% of Meridian Energy, Mighty River Power, Genesis Power, Solid Energy and Air New Zealand.
Labour says the referendum is being held at a time when people are wrapping up the year and getting ready for Christmas.
The Greens say it is appalling the Government announced it the day the sale of shares in Meridian Energy opened to the public.
Prime Minister John Key says he is not concerned about the potential outcome, given the National Party's resounding win at the 2011 election.