The AFL-CIO's Metropolitan Washington Council, in a move that could widen a serious rift in the local labor movement, yesterday suspended indefinitely its largest union, the 30,000-member United Food and Commercial Workers Local 400, because the union refused to pay its full dues.

Local 400's refusal to pay and its subsequent suspension arise from a bitter division within the 225,000-member council between public employe unions and those representing workers in private industry. Public and private sector unions have differed on several key issues in recent years, including the endorsement of Mayor Marion Barry, who was strongly supported by public employe unions but largely spurned by the private sector workers.

Thomas McNutt, president of Local 400, said yesterday his union refused to pay full dues because the council has become ineffective in representing the private sector during the leadership of Joslyn N. Williams, who was elected in 1982 as the labor council's first full-time president.

McNutt said that Williams "hasn't the foggiest notion of what is going on in the labor movement."

Williams yesterday called Local 400's departure from the council "regrettable" but said it would not hurt the council's efforts in lobbying, backing prolabor legislation, and organizing for the 1984 elections.

"It is always regrettable when there are members of the labor movement who are not in the house of labor," Williams said. "But we take the position that the whole is greater than any single of its parts."

Local 400, which represents grocery clerks, meatcutters, department store workers and many other employes, is the Washington area's largest union and one of its most politically active. From its modern $5 million office building in Landover, it has lent office space and manpower to political organizing efforts on behalf of labor-supported candidates.

The United Food and Commercial Workers (UFCW) local is the fourth private-sector union to be suspended from the council in the past two years. Those unions--including the UFCW--have joined to form an alternate labor organization called the Food and Allied Service Trades (FAST) council, which now represents about 45,000 workers and is conducting political activities independent of the labor council.

FAST, for instance, is currently preparing a petition drive to place on the 1984 D.C. ballot an initiative that would restore money cut from unemployment compensation benefits.

The cuts were enacted this year at Barry's request to help balance a $57 million deficit in the compensation fund. The labor council, in an action that exacerbated the split within its ranks, supported Barry's plan.

Conflict between public and private sector workers surfaced last year with the suspension of the 10,000-member Local 25 of the Hotel and Restaurant Employes International Union, whose secretary-treasurer, Ron Richardson, clashed frequently with Williams.

Local 25, Local 400 and other private sector unions, especially in the building trades, had opposed Barry's reelection because of what they saw as his antiunion attitude in cutting workers' compensation and unemployment benefits, and in allowing substantial city contracts to be awarded to nonunion firms.

But Barry won the support of major public sector unions such as the American Federation of Goverment Employees (AFGE) and the American Federation of State, County and Municipal Employees (AFSCME), the two unions representing most city workers. Private sector unions charged that Barry had "bought" AFGE and AFSCME by giving them sweetheart contracts in exchange for political support.

Williams, a former official of both AFGE and AFSCME, said that if Richardson and McNutt felt his leadership was poor, they could try to defeat him when his term expires in 18 months rather than essentially quitting the council.

Yesterday's suspension was approved by an 8-to-0 vote of the council's executive board, following what Williams described as an unsuccessful year-long effort to get Local 400 to pay dues according to council bylaws.

Williams said he delayed recommending the suspension because "I have been reluctant to take any action that would affect our unity. . .but there comes a time when the clock stops running."

Williams said he proposed the suspension because the union, since January, was paying only about $100 a month instead of its full monthly share of about $4,000 to $5,000. The 150 member unions are required to pay 20 cents a month per member, but Local 400 paid for only 500 members. Unions facing financial hardship may seek exemption from dues, but Local 400 consistently refused to ask for a waiver, Williams said.

"It is very unfortunate to expel Local 400. . .it has always been the backbone for political action" among local unions, said Minor Christian, the president of Local 25. Christian, who is also president of FAST, said the organization does not intend to compete or be in conflict with the central council.

"This town needs a united labor movement," he said. "I don't think we can afford a split like this at this time."