Mandatory firearm sentences blocked again

The Abbott government has failed to push mandatory five-year sentences for firearms offences through the Senate once again.

The mandatory sentences were to be part of a bill that makes multiple changes to criminal legislation. But these were stripped out by Australian Greens amendments which were backed by Labor.

The government says mandatory five-year sentences for trafficking firearms were an election commitment but the Greens say it's unnecessary to remove the discretion of the courts.

It's the second time the government has tried to get the firearm changes through the Senate.

This time the Senate passed other measures including harsher penalties for forced marriages and improved information sharing about federal offenders.

The crimes legislation changes will have to go back to the House of Representatives for approval of the amendments.