A major shareholder has revealed the high cost of electricity is threatening the viability of the factory.

"Prices (for electricity) have fallen because of renewables coming on stream, but it still needs to continue to fall to achieve the sort of returns that we need to achieve to keep the facility operating," Alumina Limited managing director Mike Ferraro told The Australian Financial Review.

Member for South West Coast Roma Britnell said the state government needed to make power more affordable for the Portland smelter to secure the jobs it provided to the region.

"High power prices are the biggest issue facing businesses right across Victoria, especially for energy intensive industries like the Portland smelter," Ms Britnell said.

"Daniel Andrews and Labor know it's a major issue, it's the reason both the federal and state government put together a package to save the smelter in 2017.

"But the state Labor Government seem to be doing little to address the problem facing large industry when it comes to energy prices."

Member for Wannon Dan Tehan said he was advocating for a reduction in electricity prices.

"One of the key commitments we took to the election was to do everything we could to put downward pressure on electricity prices because it impacts all businesses right across the region," Mr Tehan said.

"I will continue to strongly advocate for that. It's so important - not only for the smelter, but for Keppel Prince which makes wind towers, it's so important for dairy producers, abattoirs and farmers."

Mr Tehan said they all needed low electricity prices.

"It will be something I continue to push for, for all businesses."

An Alcoa spokeswoman said the Portland smelter was a well-run facility and the company remained focused on identifying ways to increase its global competitiveness.

"However, like aluminium smelters across the globe, it is facing challenging market conditions," the spokeswoman said. "Our goal remains to establish a long-term future for the smelter in the interests of our employees and the local community. Obtaining an internationally competitive power contract is central to that future.

"Our current power contract runs until mid-2021."

Glenelg Shire mayor Anita Rank refused to comment, saying there was no issue at the smelter.

Comment was sought from the state government.

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