Labour won't say whether it would step in to save the Tiwai Point aluminium smelter if successful at the next election.
Rio Tinto, the smelter's Australian owner, walked away from talks with the Government during the weekend and rejected an offer for a "reasonable" short-term taxpayer-funded subsidy.
Prime Minister John Key said the offer was meant to bridge the gap between Rio Tinto and Meridian Energy, who are in negotiations over the future electricity price for the smelter.
Key said the Government would not offer long-term support, as was on offer in Australia, but agreed to look at short-term assistance because of the thousands of jobs at stake, and to facilitate a smoother transition should the smelter close.
Today, Labour leader David Shearer said he did not have the details of how much was needed to save the plant.
"I haven't seen the numbers, until we see the numbers we can't comment.
"We would be looking at the negotiations to see what we could do, but I can't give a guarantee and I certainly wouldn't be saying we would give Rio Tinto an open cheque book."
Key needed to be more transparent about how much had been offered to Rio Tinto and what was needed to bridge the gap long-term, he said.
"What we don't want to see is a Sky City or a Solid Energy type of activity going on here."
The Government should put off the sale of Mighty River Power when there was so much uncertainty around electricity prices, he said.
But Key has said the partial float will go ahead, with more details expected to be released on Friday.
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