The 1049-berth car park has been used by the hospital since 1996, but site owner Macquarie International Health did not renew the lease in November last year and took over the site, reducing to 600 the number of car parks available to staff.

The change comes as a health district official said plans for a new car park on the campus had been completed.

Some staff who had been using the car park for years were no longer able to get permits, leaving them to scrabble around Newtown for unmetered parking or catch public transport.

Meanwhile, the parking fee increased from $25 per fortnight to $5 per exit, ratcheting up to $7 per exit in March and $12 per exit last week – or $20 for those who do not have a permit.

About 50 per cent of 63 nurses surveyed by the NSW Nurses and Midwives Association said they would consider resigning over the car park issue.

Cardiologist Lynne Pressley said registrars who were rostered on-call could pay $160 to $200 for car parking over one weekend.

Three very senior doctors – including an anaesthetist, a cardiologist and a radiologist –were considering whether to resign, said Dr Pressley, a member of the Australian Salaried Medical Officers Federation.

"It will have a deleterious effect on the standard of care delivered at our hospital for years and years to come," Dr Pressley said.

"No one is going to want to get jobs here when there's no parking. [Medical trainees] get called in at all hours of the day and night. It's not like they can use public transport."

Sydney Local Health District has organised a free shuttle to Redfern train station and has negotiated with the Ports Authority for staff to park at White Bay with a shuttle service to the hospital while a new car park is built over the next 12 months.

SLHD chief executive Teresa Anderson told staff in a memo this week that plans for a new car park had been completed and funding secured.

"The site has been identified which, pending some final details, I will be able to share with you imminently," Dr Anderson said.

"The board and executive of SLHD and RPA recognise that the car parking situation is continuing to cause significant frustration and inconvenience for many of you.

"The construction of the new staff car park will address this in the medium term, providing additional staff car parking on the campus, but we hope that the interim plans including the off-site parking, which is not ideal, will help to alleviate the problems you are experiencing in the short term."

A spokeswoman said separate arrangements would be made for on-call staff.

"We are very fortunate to have highly skilled, talented and loyal staff," she said "We have been working hard at providing parking alternatives to support our staff in their exceptional work."

It is understood Macquarie Health asked the Sydney Local Health District for a list of staff who were allocated parking permits, but the health administrator was advised by lawyers not to give staff details to a private contractor.

Parking contractor Secure International then handed out forms to staff to fill out as they arrived or left the car park over two weeks, but those who were away on annual leave or doing placements in rural hospitals missed out.

NSW Nurses and Midwives Association organiser Nola Scilinato said car parking could be the "straw that broke the camel's back" for nurses considering whether to resign.

"I don't believe they're going to go in hordes but I think over time people will move on and that will be really sad," Ms Scilanto said.

"The members just want to be able to go to work, have affordable parking and get home safely."

Secure International did not respond to requests for comment.