The RTWSA proposal would tighten the Impairment Assessment Guidelines (IAG) which injured workers are evaluated against to determine whether they are eligible for compensation.

Currently, if a worker’s injury affects more than five per cent of their bodily capability, they’re entitled to a lump sum payment. If their injury affects more than 30 per cent of their bodily capability, they are deemed “seriously injured” and are entitled to ongoing income payments as well as a lump sum payment.

The proposed reforms would see 10 per cent deducted from an injured worker’s assessment if they have a pre-existing injury, prompting backlash from unions and the legal and medical sector who say thousands of workers could miss out on compensation payments.

RTWSA first floated the changes in a draft paper issued to stakeholders on May 28, with an intial four-week consultation period concluding on June 25.

Under the Return to Work Act 2014, Lucas as minister for industrial relations can approve amendments to the IAG – bypassing the need for legislative review – after a consultation period with medical practitioners who undertake impairment assessments.

Lucas revealed in Senate Estimates on Wednesday that the consultation process with the Ministerial Advisory Committee – which he said was “overwhelmingly” comprised of medical and union legal representatives – was extended until the last week of July.

“They asked whether I could extend [the consultation period] for them, I gave them an extra month,” he said.

“They’ve provided advice within that particular timeframe, and then in the last few days Return to Work SA having considered that advice and everything else has now given me some recommendations as to what, in their view, I should pursue.”

But Lucas declined to reveal the contents of the RTWSA advice which will inform his decision.

“I’ve got to consider the recommendations from RTWSA. I’ll make a decision and once I take that decision … [it] will be there for all and everyone to either applaud or oppose,” he said.

SA Unions secretary Dale Beasley said pushing through with the reforms without oversight would add “insult to injury”, telling reporters after the hearing that unions were left out of the consultation process.

“There has been no discussion with unions who represent injured workers. There is no Parliamentary oversight of these dramatic changes,” Beasley said.

“Medical specialists who understand workplace injuries oppose the changes. Lawyers who understand the law oppose the changes and unions who represent workers demand that the government drop these changes.”

Lucas also told the estimates hearing the State Government would conduct an independent review of South Australia’s GST agreement with the Commonwealth.