Dock operator Patrick has warned its workers they will not be paid if they begin work slowdowns on Australia's major docks on Wednesday.
Restrictions in Brisbane and Sydney are scheduled to begin Wednesday morning, with Fremantle to follow on Thursday.
According to ABC News, the industrial action is set to continue after last minute calls for negotations.
Patrick issued staff with the pay withholding warnings via text messages last night, but denies the measure amounts to a lockout.
"Patrick is allocating employees for shifts in all of our terminals as per normal, however due to the severity of the bans, which render our operations inoperative we will not pay employees
unless they are willing to work their full duties in accordance with the Fair Work Act," Patrick director Paul Garaty said.
"The nature of these bans means that vessels cannot be serviced. So if Patrick were to pay it would be paying employees even though they are not working.
"This is fundamentally different to a lockout where an employer prevents employees from working."
Workers in Sydney arrived at the dock at 6am (AEST) on Wednesday and are now meeting with management on site.
Patrick has also confirmed it extended a formal invitation to the Maritime Union of Australia to enter into last-minute voluntary conciliation and arbitration before the Fair Work Commission.
Patrick believes the restrictions could log-jam about half of Australia's container trade.
The MUA wants three annual six per cent pay rises and an increase to superannuation from nine to 13 per cent.
Patrick says the union's pay claim would add about $120 million to the company's costs over the three years without productivity offsets.
