UPDATE 2.40pm: BHP Billiton's iron ore boss has entered the fray over a looming tugboat strike at the Port Hedland, suggesting the mining giant is growing increasingly worried about the possible impact on productivity and profits.
The Maritime Union of Australia has threatened strike action by tugboat operators over an enterprise bargaining dispute with Teekay Marine Pty Ltd.
In a media statement, Jimmy Wilson warned that any action by MUA members would have severe consequences for Australian exports and would damage the country's international reputation.
"Industrial action by the MUA will stop all shipments out of the port and cost exporters like BHP Billiton, Fortescue Metals Group and Atlas Iron about $100 million a day," he said.
"In addition, the State and Federal Government stand to lose tens of millions of dollars a day in royalties and corporate tax revenue," he said.
Mr Wilson argued the MUA was pursuing an unacceptably high salary rise of almost 10 per cent a year and an increase in annual leave without any link to improved productivity.
"Teekay's maritime union employees at Port Hedland are already the highest paid in the towage industry in Australia," he said.
"Their demands are unreasonable and out of touch with the current economic conditions faced by Australian exporters."
MUA's assistant WA secretary, Will Tracey, said recently the main sticking points revolved around annual leave and pay.
The union is seeking to secure four weeks annual leave for deckhands, who currently get none, arguing it is an entitlement that applies across the industry.
Mr Tracey said workers also wanted deckhands' pay to be brought closer into line with a Master's rate, claiming the gap was relatively big in Port Hedland and it was unfair.
"Industrial action is always a last resort and we still hope that we can come to an agreement without having to take the action which has been sanctioned by the Fair Work Commission," Mr Tracey said.
"We understand that Port Hedland is very important to the Australian economy and so we want to ensure that the best tugboat workers can be attracted to work at such a remote location.
"The best way to do this is to ensure the right wages and conditions are put in place."
BHP shares closed down 28 cents, or 0.75 per cent, at $37.17.