Critics of U.S. aid to anti-government rebels in Nicaragua have the votes in the Senate to halt the program, Sen. Patrick J. Leahy (D-Vt.) said yesterday.

Emerging from an intelligence committee meeting with Secretary of State George P. Shultz, Leahy said, "I think the administration is finally getting the picture that there will be no more covert aid."

Leahy, who is committee vice chairman, said many senators are concerned about atrocities allegedly committed by the rebels, known as "contras," against Nicaraguan civilians.

"I'm convinced there aren't enough votes in the Senate for a further covert action program," he continued. "The administration is going to have to stop trying to substitute a covert action program for foreign policy."

On Oct. 3, in its most recent Senate test vote, the covert aid program passed, 57 to 42, with one critic absent. At least two more senators have announced since then that they will oppose its renewal when it comes up again in March. And two critics joined the Senate, according to a count by the Center for National Security Studies.

Thus, 47 senators now openly oppose the program. That would leave the critics four votes short of a majority, although other votes may have shifted. Administration supporters say an apparent crackdown on dissidents within Nicaragua may have moved some senators back to favoring aid for the rebels.

The House has voted three times to end the program.

Administration officials have made it clear that they regard the aid program as central to their policy of pressuring the leftist Sandinista government of Nicaragua into domestic and international policy changes. White House spokesman Larry Speakes said yesterday that the administration will ask Congress for "support of our entire Central America program," including the contra aid.

Committee Chairman David F. Durenberger (R-Minn.), one of those who recently changed position, said, "I think it healthy that the administration is looking at a variety of options" for pressuring the Sandinistas.

Shultz and Morton I. Abramowitz, director of intelligence and research at the State Department, met for 90 minutes with the committee, which has nine new members, in what one staff aide described as a get-acquainted session.

The committee said the discussion covered the relationship between policy and intelligence gathering, the threat of international terrorism, arms control verification and the situation in Nicaragua.

"Shultz and the committee agreed that there should be greater contact between the committee and the State Department . . . on a routine basis as well as in crisis," the statement said.

Also yesterday, the Associated Press reported that two authorities on Central America urged Congress not to approve new aid to Guatemala, arguing that the Central American nation's much-applauded "democratic opening" masks continued brutal abuses of human rights by military forces.

But another Central American specialist said improvements in human rights and progress toward democracy are trends that should be encouraged by renewing aid.

Georges A. Fauriol of Georgetown University's Center for Strategic and International Studies told a House Foreign Affairs subcommittee that failure to approve "a measured package" of economic and military aid for Nicaragua "would be tantamount to abandoning a democratic spirit that now exists in Guatemala to the ravages of left -- and right -- extremism."

Lord Avebury, chairman of the Human Rights Group in the British Parliament, said, however, that there has been no improvement in the human-rights situation in Guatemala.

"If anything, it has worsened since 1983," he said.