RHH project director Ben Moloney said in a statement Friday morning the lead contractor had terminated its contract with AMS Hydraulics in what was a commercial matter between the two companies.

“The Managing Contractor will immediately fast track the appropriate procurement of a new hydraulics subcontractor,” Mr Moloney said.

The Communications Electrical and Plumbing Union claimed last week 20 workers had been "sacked without notice" in a further setback for the site.

In September, up to 120 plasterers stopped work on the site after claiming they were not paid for up to eight weeks of work. Unions also estimated Chinese and Taiwanese workers were owed $1 million in wages.

Mr Moloney said the project would continue to receive regular briefings from John Holland Fairbrother and monitor the resolution of the matter.

“The delivery of the project remains on budget and the Managing Contractor’s forecast date for practical completion of the building works remains mid-2019,” Mr Moloney said.

Health Minister Michael Ferguson expressed his disappointment on Friday morning that commercial issues were not able to be resolved between the two parties.

Mr Ferguson said he had asked for "every option" to be explored to see the works recommence as soon as possible with local workers and apprentices prioritised, reiterating the importance of both safety and deadlines.

“We've achieved so much and are so close to realising the benefits of a redevelopment that has been talked about for so long, but is being delivered this year," he said.

"The public can be assured of the Liberal Government's determination to see the plumbing works resolved swiftly.”

AMS Hydraulics and the union have been contacted for comment.

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