The government's largest employee union will learn next week whether its 285,000 civilian members want to begin organizing uniformed personnel in the Army, Navy and Air Force.

More than 1,000 of the 1,500 American Federation of Government Employee locals - from Panama to the Pentagon - already have voted on the question of expanding into the military. Those sealed ballots are under lock and key at the AFGE headquarters. They will be counted Tuesday and the results made public the next day.

If the AFGE membership votes against organizing the military - and many members are opposed to the idea - that should end the question of unios in the military for the time being. Other big groups, like the Teamsters, who were once studying the idea of organizing the armed services, have said they will not attempt it now.

If the big AFL-CIO affiliate, which represents more than 600,000 white and blue collar government workers, does get the green light from its membership, leaders here and in the field are prepared to mount a vigorous recruiting campaign that could bring the AFGE into conflict with Congress and the Defense Department.

Forty-nine senators have cosponsored legislation that would bar unions from the military. That bill has cleared the Armed Services Committee. The Pentagon has said it opposes unions in the military, and Defense recently published administrative rules that would prohibit on-base solicitation of members by unions, and would bar unions from representing military personnel on most matters.

Although most AFGE national officers want to begin organizing the military, the union has done an excellent job of proving balance coverage an giving equal time to "pro" an "con" arguments on the subject.

AFGE leaders and members who favor going into the military say that it would increase their income through a new influx of members and also boost their political clout on Capitol Hill. They point out that plans for organizing the military would not interfer with any combat operations or tactical exercises, and that no "shop steward" would even think of encouraging soldiers to disobey an order.

Opposition comes from members who fear that the civilian-oriented union would dilute its efforts toward long-time members by being required to service new types of complaints from military personnel.

They also fear that the first wave of new members would come from the ranks of military personnel whose grievances and demands for service would take up more time and money than they would be worth. They also do not like the idea of antagonizing Congress and the Defense establishment, which employees nearly half the union's civilian members.

Last year at the AGFE convention in Las Vegas, delegates voted to change the civilian-only membership provision of the union convention. They left the decision whether to organize the military up to AFGE leaders. They in turn called for the nation-wide vote by locals. The results should be known Wednesday, and it could mark and entirely new course for the union and the armed forces.