Ryan Kelly, Mining and Energy Union (MEU) member and Peabody worker, said around 20 workers from the coal processing plant had been locked out by the company, Peabody Energy, since June 18 after ongoing employment agreement negotiations.

Workers had decided to bargain terms of a new contract, and according to Mr Kelly, Peabody wanted to strip clauses from the agreement that put their job security at risk.

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Mr Kelly added that workers were offered a 2 per cent pay rise, which was not enough to match inflation that currently sits at 6.1 per cent.

"They decided to strip out a few major clauses in relation to the true meaning of permanent crew, and to strip away job security clauses so they can get sacked at any time and be replaced by contractors," Mr Kelly said.

"You can't function in today's society without job security. We really need that back and we need it to stay.

"And then by taking all of that stuff and offering us 2 per cent pay rise ... is just not fair on the workers."

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Workers were locked out of the mine after they took an hour and 20 minutes of protected industrial action last month, Mr Kelly said.

"It's been hard on the family," Mr Kelly said. "But they (Peabody) don't seem to be wanting to come to the bargaining table at all."

Mr Kelly said the workers will be let back to work if they promise to not take further industrial action.

"But that's the only course of action we have if we want to try and fix this up and get those clauses back," he said.

"It's all about safety, and job security. If the workers are at work and are safe and secure, your mind is a lot safer because your mind is not elsewhere worrying about other things like if I make a mistake here, someone's gonna come and sack me."

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However, a spokesperson for Peabody Energy said the workers could notify the company if they wished to return to work under the existing conditions of the employment agreement.

"We remain positive in progressing the negotiations through the appropriate Fair Work Commission processes and look forward to a time when our employees can return to work," the spokesperson said.

The Mining and Energy Union (MEU) members will take their plight to Canberra on Tuesday to speak with secretary of the Australian Council of Trade Unions, Sally McManus.

Both parties - Peabody and the MEU - are taking the normal legal actions available to them under Fair Work Commission process.

Unionists gathered on Sunday to remember the 96 miners who died in the Mount Kembla explosion that occurred 120 years ago, and to highlight issues surrounding workplace safety.

South Coast Labour Council assistant secretary Mick Cross also took the opportunity to express support for the Peabody workers.

"We're joined in struggle by comrades from Helensburgh mine in the washer who are locked out at the moment by a company refusing to sit down and negotiate in good faith with them over their agreement," Mr Cross said.

"It doesn't matter what industry we are in, if workers don't fight and don't struggle as one, we won't win a thing."

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