An imposing, 10-foot-high photograph of Mayor Harold Washington hung about the dais at the annual Cook County Democratic Party dinner Wednesday night, but the new mayor was miles away describing his feud with the party organization as "war."

He and the rest of the city's black political leaders were on the South Side at a competing "strategy session" dinner of their own, called to protest "the prejudiced" and perhaps "racist" activities of the Democratic organization and its chairman Edward R. (Fast Eddie) Vrdolyak.

Vrdolyak, who has led a revolt of 29 white aldermen against Washington, played down the significance of the black boycott, predicting that "We'll be back together again."

But if there was any hope that the deep divisions in this city's once powerful Democratic organization were being healed, Washington dispelled them in a tough, campaign-like speech.

"This is not a chess game," Washington said, referring to his battle with Vrdolyak. "This is no Mickey Mouse business. This is war.

"They're trying to make this a racial division," he added. "It's not that at all. It's good versus evil."

The black dinner, a hastily arranged affair attended by several hundred, was held at a small restaurant called Army and Lou's. The regular party dinner, traditionally dominated by the mayor of Chicago, was a far more imposing affair, filling nine ballrooms at the Conrad Hilton Hotel in the Loop.

The two places are about nine miles from each other, but symbolically they are much further apart, as are Washington, Chicago's first black mayor, and the white majority on the City Council after his first month in office.

Washington's battle with Vrdolyak has stalemated the City Council since his inauguration on April 29. And there are few, if any, signs of any end to the fight. Wednesday and today, for example, a routine application for a $147 million federal grant tied up the council for more than nine hours of debate.

Many council members now predict that the struggle may go on in one form or another for most of Washington's four-year term. Grayson Mitchell, the mayor's press secretary, blames this on the refusal of white machine politicians to deal with the reform-minded new mayor.

"Every move the mayor makes, they make a countermove," he said. "They are obviously trying to emasculate the office."

But some of Washington's staunchest supporters are beginning to express displeasure with him.

"I'm very frustrated. I think he still thinks he's campaigning, and he's playing to the black audience," one pro-Washington alderman complained. "It's absurd. He won and it's time for him to start governing. I think he's setting himself up for defeat in four years and he's giving credence to the notion that blacks and reformers can't govern."

The most immediate conflict is over the organization of the city council. Vrdolyak, an alderman as well as party chairman, controls 29 of the council's 50 votes and stripped black aldermen of eight key committee chairmanships, replacing them with his allies. Last week Washington lost a key court test of the move, but he appears determined to pursue every legal avenue rather than compromise.

"There will be some surface making-up in a few weeks after the next court decision," Alderman David D. Orr, a Washington supporter, said. "But in terms of the struggle for real political power we're in for a long fight that will go on for four years."

The dinner still was a financial success, raising $700,000 toward repayment of a $800,000 party debt.