The D.C. Council voted yesterday to block the Barry administration's plans to furlough up to 26,000 city workers this summer, adopting emergency legislation that requires the government to give employees three months' notice before taking such action.

The council also approved emergency legislation to subsidize medical insurance for employees of the Whitman-Walker Clinic, a major AIDS service organization that says it could be wiped out by the escalating cost of its health premiums.

Council members approved both the furlough and Whitman-Walker measures without debate and by voice vote, a testament to the powerful election year forces dominating the local political agenda.

Some council members had previously expressed skepticism about both measures, but no opposition was voiced to the bills, which were backed by organized labor and gay-rights activists.

The council, which met for the last time before a summer recess, also authorized $278 million worth of borrowing to finance capital projects in the District. And it passed a bill requiring police to make arrests in domestic violence situations where there is probable cause that a crime has occurred.

The Women's Legal Defense Fund hailed passage of the domestic violence bill as protection for women, adding, in a statement, that "right now, District police very rarely make arrests, even if the victims are bleeding, have broken bones or are injured so badly they must be hospitalized."

In recent days, the city's major labor unions pressed the council to kill the administration's plan to furlough city workers for four days this summer. They threatened political retaliation against those members who did not support them.

The bill approved yesterday extends the notice period the city must give workers from 30 to 90 days before a furlough can take effect, precluding the city's furlough plans this summer.

Labor officials had said before yesterday's vote that they would consider the furlough issue in deciding whom to endorse for mayor and D.C. delegate this year. Four council members running for mayor and D.C. delegate are seeking the endorsement of the metropolitan area AFL-CIO, which is scheduled to make its endorsements Monday.

John A. Wilson (D-Ward 2), chairman of the council's Finance and Revenue Committee, said it was unfair to tie the mayor's hands in attempting to reduce a deficit when the council is unwilling to go along with his proposal to raise taxes.

But he said, "we didn't have the votes" to defeat the bill that blocks furlough. "I was going to lose, so what was the purpose" of trying to fight it, he added. "The big problem is that we're in an election year."

Wilson questioned the tactics of council member Betty Ann Kane (D-At Large), the sponsor of yesterday's anti-furlough measure and a fierce opponent of a tax increase. Kane is giving up her council seat in running for D.C. delegate.

"She's not going to be here anyway {after January}, so what difference does it make to her," Wilson said.

Kane defended her action, noting that a furlough would save the city only $2.5 million while amounting to a 20 percent reduction in city services while the furlough is in effect.

"I'm not asking people to pay the same taxes and get fewer services," she said. "The furlough would mean a loss in revenue for the city because if you cut the wages of employees 20 percent, then you reduce the tax they would pay."

Administration officials who opposed the Kane measure said, after yesterday's vote, that there is a chance that Mayor Marion Barry will veto the measure, either directly or by refusing to sign it.

"The action on the furlough does further restrict our ability to balance the budget," said Robert Pohlman, the District's deputy mayor for finance.

Garland Pinkston, Barry's top lobbyist with the council, said he would recommend that Barry veto both the furlough bill and the Whitman-Walker measure, a bill that has also been the subject of intense political jockeying.

Under the legislation approved yesterday, Whitman-Walker and four other nonprofit health clinics would, together, receive about $250,000 annually in subsidies for their health insurance.

The bill was aimed primarily at Whitman-Walker, where health premiums have more than quadrupled since January 1989.