Hundreds of Chevron workers could walk off the job again amid allegations the oil and gas giant reneged on a commitment to the industrial umpire.
A strike at the company's Gorgon and Wheatstone gas plants in Western Australia could disrupt global supplies and unsettle prices.
Workers at the facilities voted to restart industrial action if further talks with Chevron also fail, an Offshore Alliance spokesman told AAP on Friday.
Union officials met with day shift and offshore staff at the facilities in West Australia's northwest late on Thursday for a ballot.
They're scheduled to brief night shift workers on Friday afternoon and could file protected industrial action notices on behalf of about 500 workers in the days following.
Unions must provide seven days' notice before any stoppages can start at the Pilbara sites, which supply about seven per cent of the global LNG market.
"Chevron have reneged on the commitment they gave to the Fair Work Commission to incorporate the FWC's recommendations into the Chevron (enterprise bargaining agreements) for the Wheatstone and Gorgon facilities," a union social media post said.
"Once again, Chevron's industrial integrity has been found wanting."
Chevron Australia said it had worked hard to finalise the labour agreements to provide market-competitive remuneration and conditions to its employees at the sites.
"We have accepted the recommendation of the Fair Work Commission, which proposed terms to resolve outstanding claims that would form part of the proposed agreements," a spokesman said.
"We continue to work with all parties to finalise the drafting process based on the recommendation."
Protected industrial action started on September 8 at the Wheatstone platform, Chevron's downstream processing facility of the same name, and the Gorgon downstream processing facility.
It ended almost two weeks later when Chevron and the unions accepted the industrial arbitrator's proposals on pay and conditions.
Gorgon and Wheatstone supply 44 per cent of WA's domestic gas and revenue from the projects is estimated to be $76 million a day, according to research group EnergyQuest.
Chevron had been the last major producer in the WA gas fields without an EBA after workers at Shell, Inpex and Woodside signed off on agreements of their own.
Chevron
