Prime Minister John Key says he will push ahead with partial asset sales - regardless of whether or not opposition parties gather enough signatures for a referendum.
The Labour and Green parties, Grey Power and the Auckland University Students Association on Friday launched a final push to collect enough signatures.
So far the petition has 240,000 and needs 310,000 to trigger a non-binding referendum. The Greens say the campaign is on a roll and there could be enough to force a referendum by early next year.
Mr Key said on Friday it is up to the Government to determine when a referendum would be held and it is ready to deal with potential obstacles, such as legal action by Maori or falling revenue for some of the state-owned companies tagged for partial sales.
However, he said a citizens initiated referendum would not stop the Government from pressing ahead.
"We had the biggest referendum we're going to have - which was the general election. We won with the largest majority National has in living history, other than the 1951 waterfront strike result.
"(Partial asset sales) was the major issue that was debated during the election campaign and National got an overwhelming majority going to the public with that policy."
But Labour Party leader David Shearer says the state of several of state-owned enterprises due to be partially sold including Solid Energy, which reported a $40.2 million loss on Friday, will set back the sale process significantly.
"Air New Zealand - that's well down the list. Meridian (Energy's) talking with the aluminium smelter about future power prices that it's going to be charging them, the Maori issue around water rights around Mighty River Power - all of these issues are going to be delaying the sale."
Mr Shearer says there is so much opposition to asset sales it should be easy to get the remaining signatures needed to force a referendum.