The federal government is poised to announce a national gun amnesty following an unprecedented wave of violent firearm-related crime in Melbourne.

State and federal ministers and attorneys-general requested an amnesty be considered by senior officials in the National Justice and Policing Senior Officials Group last year.

These officials gave a unanimous in-principle support for an amnesty last month.

State ministers must agree to proceed, however, support for an amnesty is strong and it is understood the timing will be settled before the end of the year.