While each of the three main parties have all told the Australian Nursing and Midwifery Federation ACT branch they were committed to safety, none have promised a specific, legislated ratio.

The Queensland government in May introduced legislation to mandate ratios of one nurse to every four patients during day shifts and one nurse to every seven patients at night.

ANMF ACT branch secretary Jenny Miragaya said the union was particularly concerned a shortage of nurses and midwives was not being effectively managed, with nurses "becoming exhausted because of the need to do extra shifts and overtime".

The ACT Labor Party has said it was committed to safe staffing levels, while the Liberal Party and the Greens have both indicated they were willing to consider mandatory ratios, but the pledges have fallen short of the guarantee being sought, Ms Miragaya said.

The union's call for "safe staffing levels" follows a Monash University study released this week that showed more than 30 per cent of nurses surveyed nationally had considered leaving the profession due to being overworked and undervalued.

It forecast a coming shortage of nurses and midwives nationwide, with the majority of the workforce in Australia already aged 47 years or older, at a time when the federal government has forecast a potential shortfall in the workforce of up to 85,000 by 2025.

The results of the annual survey of 3000 nurses and midwives showed all indicators for "work intensification" had increased every year since it began three years ago.

"The only way we are going to fix these problems and ensure the safety of the public is by introducing mandatory safe staffing levels," Ms Miragaya said.

But she said New South Wales, Queensland and Victoria had already promised or legislated mandatory staffing ratios.

"It's time the ACT followed suit," she said.