Speaker Sue Hickey votes against government bill seeking to legislate minimum mandatory sentences for assaults on frontline workers

Ms Hickey had to cast the deciding vote on the bill and sided with Labor and the Greens who voted against the legislation due to its inclusion of mandatory minimum sentencing.

"I believe sentencing should be left to judges and magistrates to consider as they have the appropriate training to make a judgement on the information specific to each case," Ms Hickey said.

"It's important to remember that the Australian Medical Association, the Health and Community Services Union, the government's own sentencing advisory committee, members of the legal community and members of the Community Legal Centres all oppose minimum mandatory sentencing.

"The legal view is that mandatory sentencing is against the separation of power of the judiciary and the state.

"We are obliged to make good law, not populist law."

The bill sought to extend mandatory minimum sentences of six months' jail, which currently only apply to cases of serious bodily harm to police officers, to apply to assaults on ambulance officers, child safety officers, correctional services and community corrections officers, nurses, midwives, medical orderlies and hospital attendants.

Greens health spokeswoman Rosalie Woodruff said the Greens would not support the bill because they would never support mandatory sentencing.

"We will never support the interference of Parliament in the decision-making in the justice system," Dr Woodruff said.

Dr Woodruff said she was concerned the bill would create two classes of public servants between those who are in "so-called frontline positions" and those who are not covered by the bill such as teachers, tenancy officers or firefighters.

"It begs the question - what about all the other people who are working in positions where they are exposed to violence and assault as a result of their work?" Dr Woodruff said.

Health Minister Sarah Courtney said if the Greens had genuine concerns about certain public sector workers being excluded from the bill they would have moved amendments to have them included.

In defending her vote against the bill, Ms Hickey said she shared the Greens' view this legislation would create two classes of public servants.

Greens leader Cassy O'Connor said punishment did not provide a deterrent for offenders.

"If it did there would be no murders in the United States," Ms O'Connor said.

Attorney-General Elise Archer said the bill would send a strong message to the general public to keep their hands off frontline workers.

"Disappointingly, assaults on frontline workers happen far too often and it's my view, and the view of the government, that one assault is too many," Ms Archer said.

"We are dealing with serious bodily harm cases. This is entirely unacceptable."

Ms Archer said the government had the power to legislate mandatory sentencing.

"There are mandatory sentences all through our statues and we do that for certainty," Ms Archer said.

Franklin Liberal MHA Jacquie Petrusma said in her previous work as a registered nurse and volunteer ambulance officer she experienced the dangerous situation frontline workers are confronted with every day.

"When alcohol and drugs are involved, thing get out of control very fast," Ms Petrusma said.

"We do want to see a deterrent put in place."