The New Zealand government won't put any more money into saving the Tiwai Point aluminium smelter, Finance Minister Bill English says.
The smelter's owners and Meridian Energy have struck a three-year deal for cheap electricity that has secured its immediate future and protected about 800 jobs.
It's going to cost taxpayers $NZ30 million ($A26.83 million) to keep the state-owned energy company's prices at a level the smelter says it can afford through to 2017.
Asked what would happen if situation was repeated in three years, Mr English said the government wouldn't be interested.
"They may try that, but they certainly wouldn't get another bite of the cherry from this government," he told reporters.
"They've negotiated a long-term contract with Meridian. I think the public expects them to get on and make their business work."
Mr English is defending the deal against opposition criticism that the government botched the deal and Tiwai Point's owners, New Zealand Aluminium Smelters, had ministers over a barrel.
The smelter has been losing money because of low international aluminium prices and the high New Zealand dollar - its owners said cheap power was essential to keep it going.
"Anyone who can take a business away has a community and its workers over a barrel," Mr English said.
"It could, theoretically, have shut down at any time and that's now not possible because of the guarantees that have been underwritten."
He acknowledged the deal would help the government sell shares in Meridian when the company is partially privatised later this year.
"It does support the float, it gives investors more certainty about what they're buying into," he said.
The union representing the smelter's workers has welcomed the deal, saying 800 direct jobs and another 2400 indirect jobs rely on keeping it viable.
"It's concerning that the agreement only guarantees the smelter will stay open for a few more years, but our members and their families now have some breathing room," said EPMU Invercargill organiser Trevor Hobbs.
