The 1.9-million-member International Brotherhood of Teamsters is making a strong effort to oust the union that for 30 years has represented the 2,300 employes of the troubled D.C. prison system.

With a union vote scheduled today, the Teamsters have brought in dozens of outside organizers and spent considerable time and money in its effort to defeat the American Federation of Government Employees.

Jail overcrowding, poor and dangerous working conditions and low wages have been among the issues in a hard-fought election campaign that ends with balloting today at D.C. Jail and Lorton Reformatory.

The outcome will determine whether the Barry administration will continue dealing with the same labor union or will have to adjust to the Teamsters, which have never represented city workers. Current contract negotiations have been suspended pending the vote.

The Teamsters have portrayed AFGE as weak and ineffective, while AFGE has countered by picturing the Teamsters as corrupt and money-hungry. Both unions describe themselves as best qualified to fight the Barry administration for prison improvements.

Dissatisfaction with AFGE Local 1550 peaked last year when more than 50 percent of the union members petitioned the D.C. Public Employee Relations Board for the right to join other unions.

More than 70 percent of the D.C. Department of Corrections voted Feb. 19 in a three-way contest between AFGE, the Teamsters and the Fraternal Order of Police. AFGE received 48 percent of the vote, but the Teamsters forced today's runoff election by receiving 28 percent and denying AFGE the 50 percent needed for union recognition under city labor law.

Leaders of the FOP, which got more than 20 percent of the vote, endorsed the Teamsters after last month's vote, increasing the possibility that today's vote may be a close one.

"People are dissatisfied with AFGE. Their wages are inferior to anyone else in the area, and the AFGE hasn't pursued their grievances. They've left these people at the bottom of the barrel," said Ernie V. Jumalon, secretary-treasurer of Teamsters Local 246.

The Teamsters say they can bargain and pursue union grievances more aggressively because they have a larger "outside staff" than AFGE. Because AFGE elects its own members to handle grievances and other matters, "they are more easily intimidated by the city," Jumalon said.

The Teamsters, the nation's richest and most controversial union, has been expanding its organizing efforts in law enforcement in recent years. The union currently represents Metro transit police.

AFGE, which was forced to put Local 1550 into receivership last year because of "mismanagement," has assigned two full-time outside staffers to the local union and has pledged to step up its prison-reform and pay improvements.

Corrections officers earn between $15,000 and $21,000 base pay, plus overtime, and trail far behind area law enforcement employes. AFGE, which represents about 7,700 D.C. workers, prodded the Barry administration to conduct a "pay parity" study aimed at demonstrating the need to raise pay to attract and retain qualified prison workers. Results of the study are expected soon.

AFGE filed suit last week in D.C. Superior Court to reduce severe crowding at D.C. Jail, and the union also is lobbying the City Council for increased spending and other action to attack what it calls a crisis situation in the prisons.

AFGE, while acknowledging some of its past failures, says its political contacts and lobbying ability in city government make it better qualified than "the other union" to get things done in District government.

"When the Teamsters came in with the Teamster jackets and Teamster hats and Teamster everything, people were impressed at first," said Bernard Demczuk, AFGE political organizer, "but people also appreciate the things we've done, and they know how hard we are working for them."

AFGE has stressed that Teamster dues are higher, starting at $18 a month compared with $13 a month, and AFGE also has focused on the Teamsters' past record of corruption and big spending.

AFGE campaign literature has focused on Teamster President Jackie Presser's $500,000-plus union salary, his $550,000 union-paid Washington condominium, and his maintaining a French chef and barber on the union payroll. AFGE also has distributed literature describing the Teamsters' 1957 expulsion from the AFL-CIO, and the indictments or convictions of four past Teamster presidents, including Jimmy Hoffa.

"This is the traditional old stuff people always try to hit us with," said Jumalon, a 26-year Teamster official based in Fairfax. "We are trying to talk about issues and they are bringing up the same old stuff."