The federal government has called a three-month national gun amnesty, the first since the Port Arthur massacre in 1996.
Government said the amnesty – where people can hand in their guns, no questions asked – was being held against a backdrop of an increased threat of terrorism and ongoing gun violence.
Justice Minister Michael Keenan said the amnesty was due to begin on July 1.
"The fact [is] we've got a deteriorating national security environment," Mr Keenan told ABC radio.
"We've got an environment where there has been five terrorists attacks on our soil and, sadly, in the vast majority of those cases it has been an illegal firearm that's been used."
The government estimates there are 260,000 illegal guns in the community.
"The danger there is that there might be a circumstance where the wrong person - a criminal, a terrorist - might get their hands on those guns," he said.
Mr Keenan said the amnesty would allow people to hand in guns with no questions asked.
"We don't want those guns to be able to fall into the wrong hands," he said.
Fellow cabinet minister Christopher Pyne said if illegal guns were not in the system they couldn't be used to kill people such as Queensland police officer Brett Forte recently.
Labor is backing the amnesty.
"We would certainly encourage people to do the right thing and to hand them in," frontbencher Anthony Albanese told the Nine Network.
The Port Arthur shooting in April 1996 ended with the deaths of 35 people at the popular tourist site in Tasmania.
The gunman, Martin Bryant, was given 35 life sentences.