Law Council president Fiona McLeod SC said while the legal body supports increasing maximum penalties for firearms trafficking, “minimum penalties are never appropriate”.

“They are too blunt an instrument and have repeatedly proven not to produce the desired effect,” Ms McLeod said.

“A minimum mandatory five-year penalty would not deter hardened criminals. These kinds of criminals have already likely factored in considerable jail time as a risk they are willing to take.”

Ms McLeod noted that the important goal of the bill was being undermined by the inclusion of mandatory measures.

“Mandatory sentencing may lead to unjust punishments by forcing courts to apply a rigid standard with no regard to individual circumstances,” she said.

"For example, there have been multiple examples of individuals who have a legitimate use for firearms inadvertently looking to travel on planes with gun parts. These individuals could be in prison if these reforms were in force.”

Ms McLeod pointed to the case of former Victorian police chief commissioner, Simon Overland, who in 2010 inadvertently carried a magazine containing live rounds of ammunition on a flight from Melbourne to Canberra.

According to Ms McLeod, Mr Overland had removed a firearm from his bag but forgot to take out the magazine. She noted that under the proposed laws, he would face a mandatory five-year jail term.

“Judicial discretion is a core principle of our justice system for a very good reason,” she said.

“The world is complex and judges need to be able to adapt their sentence to the circumstances of an individual case.”