Premier Gladys Berejiklian on Thursday raised the possibility of job losses amid the COVID-19 pandemic unless the proposed pay pause was endorsed on Macquarie Street.

But NSW Labor, the Greens and the Shooters Party have flagged they will block the move in the Legislative Council, with one crossbencher arguing the coalition is engaging in "economic blackmail" during a health crisis.

Ms Berejiklian last week sought a freeze on pay rises for MPs, which was extended on Wednesday to include the entire NSW public service comprising 410,000 workers.

The freeze would save about $3 billion, which would be reinvested in public projects.

Unions NSW secretary Mark Morey has labelled the announcement an act of "economic vandalism" at a time when frontline workers such as nurses, police officers and teachers are risking their lives.

But Ms Berejiklian on Thursday encouraged the upper house to back the changes, saying public sector jobs would otherwise be at risk.

She said frontline workers had received 2.5 per cent annual pay rises since the coalition took office in 2011.

"We have a number of options before us and what we've chosen is what we believe to be the fairest option," Ms Berejiklian said.

"If this option isn't accepted by the upper house, we have to go through other options."

NSW Labor's upper house leader, Adam Searle, on Thursday said: "At the moment it looks like the government will be struggling."

Greens MP David Shoebridge vowed to block the freeze in the state's upper house where the government doesn't have a majority.

"Today's threats from the premier should be beneath any political leader, but especially now when we are trying to pull together to recover from a pandemic," he said in a statement.

"We will always stand with the 400,000 public sector workers who have kept us safe and maintained essential services."

The Shooters, Fishers and Farmers Party made it clear on Thursday it wouldn't be supporting the move.

The Australian Medical Association in NSW slammed the proposed pay freeze as inappropriate given doctors in training have, in particular, borne the brunt of the pandemic.

"While they have not been laid off, they can't work from home, they've had their education and hopes for career advancement paralysed by the crisis, and they've been taking care of some of the sickest people in the country," president Dr Danielle McMullen said in a statement.

"They have also been placing themselves at increased risk of contracting COVID-19."

The nurses union said the coalition was disingenuous to suggest it was grateful for the work done by nurses and midwives but refuse them a modest pay increase.

"They've been told they can have a pat on the back but (also) a slap in the face, and that is just so disappointing," NSW Nurses and Midwives' Association general secretary Brett Holmes said on Wednesday.

NSW reported one new case of COVID-19 on Thursday - a Queensland woman who had recently returned from overseas and was in hotel quarantine.

Almost 3100 cases have been recorded in NSW while one person is in intensive care.

Ms Berejiklian on Thursday revealed about 100,000 people in NSW had taken up free TAFE online courses offered during the COVID-19 pandemic.

Australian Associated Press