Alcoa Australia has announced it is replacing the Australian flagged and crewed Portland with a foreign flagged vessel to transport alumina from Western Australia (WA) to Victoria.

The move is opposed by the Maritime Union of Australia, which today accused the government of colluding with the company to sell out Australian seafarers and replace them with crew working for AUD2 (USD1.45) an hour.

The company, however, maintains the decision to sell the ageing vessel and charter a new one was "essential for the future viability of the smelter and the protection of more than 2,000 direct and indirect jobs in regional Victoria".

"Alcoa applied for and was granted a temporary licence for 17 voyages between WA and Portland up to October 2016," corporate affairs general manager Brian Doy told IHS Maritime.

"Portland is almost 30 years old and requires significant investment before the end of 2016 to remain operational," he said. "Alcoa is seeking to secure the most cost-effective method of delivering alumina to Portland. Reducing our shipping costs will help reduce the Portland smelter's operating costs."

In a statement the union said ALCOA had enjoyed generations of profits from Australia's resources and has been "heavily subsidised from the public purse".

"We will use whatever legal means available so those jobs don't go offshore," Mark Jones, the union's Victoria branch secretary told IHS Maritime. "Some of our guys have been working the ship 15-20 years."

Portland is due to arrive in Kwinana on 29 October, where it will refocus debate over legislation in Parliament to deregulate the Australian coastal trade, which has seen maritime industry groups, unions, and opposition parties pitted against the government, industry, and representatives of international shipping groups. The bill passed the lower house earlier this month, but is expected to be blocked in the senate.

An inquiry report released in October, however, predicted the bill failing to pass would not change the course of Australia's coastal shipping industry:

"Its slow decline is likely to continue, with the expiration of transitional general licences and ongoing changes to Australian manufacturing," it said.

In July 2015 Australian crew staged a three-week sit-in on board the Caltex tanker Alexander Spirit and in January crew held a 24-hour sit in on board the Hugli Spirit oil tanker in protest at the loss of Australian shipping.