Western Australia's government has been accused of taking a "COVID holiday" when it should have been recruiting more local health workers.

Nurses and midwives have rallied against "dangerous" staff shortages and working conditions at Perth's primary maternity hospital.

More than 100 protesters gathered outside King Edward Memorial Hospital on Wednesday in the latest escalation of tensions between health workers and the state government.

Attendees at the rally organised by the Australian Nursing Federation blew airhorns and waved signs reading "Double shifts are deadly" and "More midwives now".

It is the second major protest held by Perth hospital staff in the space of three months following similar action at Perth Children's Hospital in May.

The McGowan government has promised to open 332 new hospital beds as part of an additional $1.9 billion health investment in next month's state budget.

Health Minister Roger Cook has also outlined incentives to lure hospital workers from interstate and overseas, as well as refresher courses for experienced nurses and midwives and plans to take on more student graduates.

But ANF state secretary Mark Olson said there was little immediate relief on the horizon for nurses and midwives forced to work record overtime and double shifts, accusing hospital executives and politicians of sitting on their hands.

"They saw this shortage coming. They've been on a COVID holiday," Mr Olson told the rally.

"They sat back behind the border - they knew back then that we were short. They also knew that around 30 to 40 per cent of our nurses and midwives, according to the survey we do with the nurses board every year, obtained their initial qualification either interstate or overseas.

"So if you've got a pandemic that is blocking off the country, blind Freddie can see that that is going to have an impact on your recruitment."

The union's demands include greater permanency for hospital workers, improved nurse and midwife to patient ratios and better lighting and improved staff access at the King Edward hospital car park.

Mr Cook said he was continuing to work with the ANF and the local government on improving conditions including parking.

He touted the government's investment in health, including plans to construct a new maternity hospital at the nearby QEII medical precinct.

"The best thing we can do for the doctors, nurses, allied health support staff and the patients ... is to build them a brand new hospital," he told parliament.

Mr Olson said the new hospital would take years to deliver.

"I know that staff morale here is really, really low," he said.

"I loved being a nurse, I loved all the hours I spent doing it, but I never forgot how difficult it was in the 20 years that I worked on the wards."

The McGowan government has promised to find an additional 600 nurses over the next two years and says more than 200 are already on wards.