Eight-hundred striking miners and Solid Energy are still at loggerheads as a two-week-old industrial dispute threatens to stretch out.
The state-owned coal miner says the strike is costing it about $10 million in lost production a week, as both sides blame each other for the impasse.
An estimated 300 people marched through Westport in protest today, following pickets, go slows and overtime bans elsewhere in the country.
The dispute started when Huntly's 120 Rotowaro open-cast mine workers were locked out as contract negotiations failed with their employer, Australia's HWE Mining, which operates the mine for Solid Energy.
About 160 Huntly East underground mine workers walked out in support, followed by 400 workers at the Stockton open-cast mine in Buller and then 140 workers at Spring Creek Mine near Greymouth.
All four mines are part of a multi-employer collective agreement with Solid Energy and its contractors, which has not been ratified despite expiring months ago.
Solid Energy called on the miners' union, the Engineering, Printing and Manufacturing Union (EPMU) to end the strikes so negotiations could resume.
Chief operating officer Barry Bragg said the union had been irresponsible in drawing South Island staff into a separate Waikato dispute.
The company had told customers in Japan, India and South Africa six export shipments would be delayed. Cancelled orders could mean fewer jobs, he warned.
Mr Bragg said the four strikes had undermined progress made towards securing the long-term future for the company, improving productivity, securing orders and producing a reliable coal supply, he said.
The union was refusing to budge in the Rotowaro talks, did not want to negotiate and would not return to work until it got what it wanted, he said.
"That's not good faith bargaining, it's not acceptable to us and it wouldn't be acceptable to any employer."
But EPMU assistant national secretary Ged O'Connell questioned how Solid Energy could label the union "irresponsible".
"I am amazed that they would suspend, or be party to a suspension of part of their workforce, and then be surprised that others object to it and show unity.
"It suggests the company doesn't know the nature or the culture of its workforce."
The miner and its workers were now at an impasse. It was "a classic stand-off", he said.
The union and its members did not like to see the company lose money and workers go without pay. Mr O'Connell said Solid Energy should return to good faith bargaining.
The Rotowaro dispute centred on HWE agreeing with Solid Energy on working conditions and pay without consulting the workers, he said.
Until the issue was settled the workers, who were determined and resilient, were saying they were not going back to work.
"They are not of a mind to do that at this stage."
Mr O'Connell would not speculate on how long the miners could go without work. They were in good spirits and it looked like the strike would dig in for some time.
"It looks like everyone is dug in pretty deep."