GARDA supervisors are demanding the return of the Uzi sub-machinegun for use by detectives.
The Israeli-made weapon had been deployed by sections of the force since 1967.
But it was withdrawn from use over the past few years following a review of firearms by the authorities and has been replaced by a handgun.
However, the move has not been universally welcomed within the force and a group of officers has been lobbying for its return.
The annual conference of the Association of Garda Sergeants and Inspectors, which gets under way in Sligo this evening, will debate a call on Garda Commissioner Martin Callinan to "immediately reissue the Uzi sub-machinegun to detective branch personnel".
Some senior officers argue that the Uzi was not the most suitable weapon for an urban environment and say that its replacement in the Special Branch and district detective units, the Sig semi-automatic handgun, is a much better weapon for garda use.
However, opponents say gardai on escort duty felt more secure with an Uzi lying on their lap in a patrol car rather than having to draw a handgun from their hip.
The emergency response unit and the regional response units are now all armed with Heckler and Koch MP7s, a more modern sub-machinegun, which is capable of firing ammunition that can penetrate body armour.
Meanwhile, delegates are expected to give a hostile reception to Justice Minister Alan Shatter when he arrives to address the conference this evening.
A number of association branches were not in favour of inviting the minister this year.
Some delegates may decide to protest as he arrives.
The conference agenda focuses mainly on the ongoing protests over proposed cuts to garda wage packets.