The Maritime Union of Australia has upped the ante in its dispute with marine services company Tidewater and will next week launch a 48-hour, Australia-wide strike.
About 100 cooks, stewards and deckhands will strike for two days from 4am next Tuesday.
The workers are on a range of projects across the country, including Chevron's Wheatstone LNG project near Onslow.
While it is not expected to bring any projects to a standstill, the industrial action is significant because the agreement is considered a test case that will set the terms and conditions in other agreements in the sector.
MUA assistant State secretary Will Tracey said the union decided on a stoppage because Tidewater withdrew its previous offer.
Tidewater and its negotiating body, the Australian Mines and Metals Association, had last offered 16.5 per cent more money over four years, which the MUA has accepted. During those negotiations the major sticking point concerned the roster. The union wants four weeks on, four weeks off, in a change from the current five-week swing.
Mr Tracey said the parties were back at the starting point because Tidewater withdrew the pay offer and they were no closer to agreeing on the roster.
"We did the right thing by accepting the wage offer and they went and ripped it off the table," Mr Tracey said. "AMMA is on the public record as saying the industry can afford 16.5 per cent."
AMMA could not be contacted last night.