Shell has set a date to lock out workers from its Prelude floating LNG facility in an escalation of the tit-for-tat dispute between the company and unions.
The lock out, set for next Monday, comes after industrial action forced the temporary shutdown of the facility earlier this month.
A Shell spokesperson said the company had tried to work around the industrial action but "cannot continue to operate in the same way".
"As a consequence, we will be resorting to lock outs as the mechanism available under the Fair Work Act," the Shell spokesperson said.
"Once the lock outs are in effect people will no longer be paid if they are not mobilised to the facility."
Secretary of the Australian Workers Union, Daniel Walton, said the lock out will increase the chance of a breakdown and endanger safety at the offshore facility.
"Shell will also encounter major issues with the regulator and struggle to maintain its license to operate."
Ongoing dispute
The lock out is the latest chapter in a dispute between Shell and the Offshore Alliance, a partnership between the Australian Workers' Union (AWU) and Maritime Union of Australia (MUA).
Tensions flared last month when contractors set to fly out to the rig were told to stand down and shipments from the facility slowed.
The dispute then came to a head this month when the company temporarily shut down production aboard the facility.
The shutdown came after a new enterprise bargaining agreement proposed by Shell was voted down by 95 per cent of striking Prelude workers.
Throughout the dispute both Shell and the Offshore Alliance have blamed each other for the dispute.
Spokespeople for the Offshore Alliance have said union members working at the facility are seeking better pay and working conditions.
As part of the negotiations, unionised workers aboard have engaged in "bans", some which saw cargo not unloaded at certain times.
The facility has been plagued by technical issues throughout its working life, and temporarily shut down last year after a fire.
The developments come as gas prices around the world rise due to a shortage in supply and the war in Ukraine.
And while the facility only exports gas to overseas markets, experts have said it could have flow-on effects on Australian markets.