Labor unions representing most of the District government's 30,000 employes, angered at the city's conduct of negotiations, met yesterday to form a coalition aimed at exerting greater pressure on the Barry administration and at playing a stronger role in city politics.

The formation of the Washington Alliance of Government Employees, the first attempt by the city's public-sector unions to act as a unified force, follows eight months of labor negotiations described by participants as the toughest and most acrimonious during the decade of home rule.

"The level of frustration is very, very high," Joslyn N. Williams, president of the Metropolitan Washington Council of the AFL-CIO, said yesterday. Williams, who was not directly involved in the union meeting, said the anger is directed primarily at Donald H. Weinberg, the city's chief labor negotiator, and secondarily at Mayor Marion Barry.

"There is no hostility toward the mayor. It is just that everyone has come to recognize he is an employer . . . and unions have to look out for their interests," Williams said.

But union officials involved in the coalition said its formation could be a potential political threat to Barry, who has enjoyed generally good relations with the unions and last year set up an office of labor liaison to improve his ties with union officials. The administration's perceived stinginess in current negotiations has changed some attitudes, union officials said.

"1986 is an election year for mayor and we will be taking a good hard look at who our friends are, and who are not," said Gary Hankins, president of the Fraternal Order of Police labor committee and one of the coalition organizers.

Barry, during election year negotiations in 1982, agreed to 21 percent pay raises over three years, but took a much harder line during 1984 negotiations, citing the city's deepening financial problems. The city opened 1984 talks saying it had no money for pay raises, but ultimately settled on a three-year contract with wage increases averaging 3 to 4 percent per year. D.C. white-collar employes earn an average of $19,000 and blue-collar jobs average $20,500.

Salary negotiations have been concluded with almost all the unions, except those representing police, nurses, and the University of the District of Columbia, but the city is still involved in talks over noncompensation issues including sick leave and grievance procedures.

The meeting was organized primarily by local officials of the American Federation of State, County, and Municipal Employees and the FOP, which have both had bitter exchanges with Weinberg, head of the D.C. Office of Labor Relations and Collective Bargaining.

Several unions have accused Weinberg of failing to bargain in good faith, and anger toward him peaked last October, when the city temporarily cut off dental and optical benefits to employes in what was widely regarded as a pressure tactic. That action was overturned by the city Public Employee Relations Board.

"You might call Weinberg the great unifier," Williams said, referring to the fact that the various unions frequently have disagreed on key issues but are almost unanimous in condemning Weinberg for his conduct of negotiations.

Weinberg's hard-line tactics have helped Barry "because the mayor comes in like a knight on a white horse and resolves the problems" that Weinberg creates, Williams said. "That way the mayor stays above the fray." But Hankins said "It is finally dawning on people that Weinberg works for the mayor."

Weinberg said yesterday he was "surprised at the wailing and crying of certain unions" and noted that most of the negotiations have been successfully concluded. "I never said I was lovable," Weinberg said, "I said I was fair and reasonable."