Eleventh-hour mediations between paramedics and the NSW government will continue as they attempt to hammer out a long-running pay dispute.
The groups met on Monday afternoon without reaching a deal, with discussions due to resume at 1pm on Tuesday.
Thousands of paramedics have threatened not to renew their registration, which the government says could cripple ambulance services from New Year's Day.
The bitter dispute has plagued the Minns government for more than eight months as paramedics point to higher salaries offered to colleagues in the ACT, Queensland and Victoria.
The Health Services Union (HSU) and government officials have begun mediation before the state's Industrial Relations Commission starting on Monday afternoon.
The union rejected a pay offer last week that would have lifted salaries by an average of 19 per cent over four years.
The complex offer did not match base pay for Queensland paramedics and would leave NSW workers short-changed, the HSU said.
The union is pushing for a 20 per cent increase in paramedics' base pay, which it says reflects rising workers skills and responsibilities.
If a deal is not struck by the end of the year, 2100 paramedics have threatened to allow their professional registrations to lapse on January 1.
This means paramedics would be legally unable to attend triple zero calls from New Year's Day.
Health Minister Ryan Park warned the state's triple zero emergency system could collapse on one of the busiest nights of the year if the matter was not resolved and the government was willing to refine its offer.
"But we always have to understand that we are working ... in a budgetary challenging position," he said.
The HSU has accused the government of sharing misleading figures as part of its proposed pay rise, including claims experienced paramedics were being offered a deal that would result in them getting more than $166,000 a year.
NSW secretary Gerard Hayes says the union is looking for an increase to paramedics' base pay that reflected the value of their work, not unrealistic projections based on overtime.
"As soon as the government sees sense we can resolve this dispute," he said.
"HSU is determined to achieve a pay deal that delivers parity with Queensland to stave off the collapse of the paramedic workforce."
Opposition leader Mark Speakman accused the the government of lacking urgency in dealing with the looming crisis.
"We're now only three weeks away from the prospect of the triple-zero system collapsing and lives potentially being at threat," he said.
Premier Chris Minns said the government offered to import the Queensland pay system into NSW, but the union rejected that option because it would result in worse overtime rates and conditions, despite higher base pay.
But Mr Hayes said NSW paramedics were yet to be offered the same base pay rate as their Queensland counterparts and it should not be a "big deal" for them to get a 20 per cent increase in their standard salaries.
Australian Associated Press