Engineering, Printing and Manufacturing Union spokesperson Rob Egan said industrial action could be taken in New Zealand once contracts had expired, and that bargaining for the new multi-employer collective agreement with Solid had collapsed.

He called the current situation a “Mexican standoff” as union members were determined not to go back to work and Solid wouldn’t negotiate until everyone did go back to work.

Describing the MECA as like an enterprise agreement crossed with an award, Egan said the union traditionally tried to negotiate the single document with the biggest parties, then aimed to get subsequent parties onboard over the following year, making the agreement “an award by proxy”

While striking HWE Mining workers at Solid’s Rotowaro open cast mine might have kicked off the nationwide industrial action, Egan said it was not just about solidarity as there were issues on a mine-by-mine basis.

“Because they are all being negotiated as part of the same document, they are all legitimately going out,” he said.

Egan said striking workers at Solid’s key Stockton open cut mine had serious issues with their rostering and the way the contractor swapover was handled.

In September, Downer inked a five-year agreement with Solid to operate Stockton, starting the following month.

Downer had announced that more than 600 employees would be engaged onsite and that it would receive a management fee for its services.

But Egan said that when Downer had started up from the previous three contracting companies, it didn’t reemploy about 100 workers.

“That’s actually causing one of the problems, the fact that the Solid Energy-Downer contract has been done and dusted before our guys get to the table.”

Meanwhile, Solid chief executive Barry Brag said the union was irresponsible for drawing its staff into the dispute involving HWE Mining and its workers, who operate Rotowaro for Solid.

“Solid Energy has done all we can to offer support, both direct and indirect and through a mediator, to find a way for the current industrial action to be lifted so that we can return to good faith bargaining,” he said.

“Specifically, we’ve been working hard to find a way to help HWE Mining and their employees to resume talks.”

He said the company had not been successful and the union was refusing to budge, while viewing the action as unacceptable and not of good faith bargaining.

Brag added that the strategy of prolonged strike action had put Solid’s operations at more risk.

“The current action cost us $10 million in lost revenue in the last week. If we start to lose customer orders, then we will have no choice but to cut jobs.”

Brag said the action at Solid’s Spring Creek underground mine near Greymouth was undermining the good work done in recent months to produce a reliable supply of high-quality coal for international customers.

At the Huntley East underground mine in the Waikato, Brag said the company had been talking to the workforce and the union about moving to a seven-day roster to increase production and put the operation on a sound financial footing.

“Our customers now have no choice but to buy imported coal to maintain their businesses, but if this action continues, they’ll have to make ongoing alternative arrangements for their coal supply or, in some cases, they may have to shut down production,” he said. “We will all lose as a result.”

EPMU assistant national secretary Ged O’Connell responded to Brag’s comments, saying the company needed to start working to fix the situation.

"Solid Energy is out of touch with its workers and it needs to understand that they're on strike because they're not happy with the company's offer and have made a democratic decision to make this clear,” he said.

"Our members have made it clear to us that they will continue their strike action as is their right but we are still keen to get to the table and sort a deal out.

"We take no joy in seeing Solid Energy lose money or in seeing our members go without pay and we'd urge the company to start bargaining in good faith so we can fix this and both sides can get back to business as usual."

While the union said Rotowaro, Huntly East, Stockton and Spring Creek were the mines involved in the dispute, it added that all of the company’s mines were covered by the MECA and were fully unionised, meaning all of Solid’s production has come to a halt.