A moderate Republican group charged yesterday that the New Right had entered into "an alliance of expediency" with the Rev. Sun Myung Moon's Unification Church in a move that threatens the underpinnings of the Republican Party.

Rep. Jim Leach (R-Iowa), chairman of the Ripon Society, told a Capitol Hill news conference that his group had found a "pattern of ties" between the Unification Church, New Right fund-raisers, conservative Republican college groups and the church-owned newspaper, The Washington Times.

However, Leach's news conference quickly fell into disarray as two of the targets of the Ripon report rose to dispute the accuracy of the charges, and Leach conceded that the group's six-month study "probably" suffered from "less than perfect research and less than perfect facts." Leach said he stood by the thrust of the charges, however.

Among the accusations made at the news conference and in an article in the January issue of the Ripon Review were:

* Richard A. Viguerie, the New Right's leading fund-raiser, conducted a nationwide direct-mail subscription drive for The Times, a Washington newspaper founded by Moon's church after the failure of The Washington Star.

* Viguerie engaged in other fund-raising endeavors for the Unification Church, including a 1975 direct-mail effort for the Korean "Children's Relief Fund" in which the children received only 6 percent of the $1.5 million raised.

* The College Republican National Committee, an independent wing of the Republican National Committee, "solicited and received" money from the Unification Church in 1981 to protest Soviet actions in Poland.

* Accuracy in Media, a conservative-oriented, Washington-based press-watchdog group, benefited from low-cost or volunteer workers provided by the Unification Church.

Leach told reporters that the Ripon Society's findings showed that Moon's controversial church had "infiltrated the New Right and the party it [the New Right] wants to control, the Republican Party, and infiltrated the media as well." He called on the Republican Party to dissociate itself from both the New Right and the Unification Church.

Leach charged that the New Right and the Unification Church were "using each other" in an alliance that amounted to "hypocrisy of the highest order." The New Right generally advocates strong family ties and rock-ribbed patriotism, Leach said, while the church "seeks the disintegration of the family" and an "international social order."

Leach's news conference also disintegrated, however, when a former director of the college Republican group, Grover Norquist, broke into the question-and-answer period to accuse Leach of telling lies. Norquist denied that his group had sought or taken funds from Moon's church.

"This is not just a lie," Norquist said, "it's charging us with a federal crime." Acceptance of church funds by an election group violates federal election laws.

Later at the news conference, Bernard Yoh, communications director for Accuracy in Media, angrily rose to accuse the Ripon group of quoting him out of context.

The report quoted Yoh as saying he is "glad there is an organization such as the Unification Church that is so effective in training youths." Yoh said the full quotation dealt with training youths to avoid drug use and other abuses. Leach apologized.

Viguerie, who did not attend the news conference, wrote off Leach's charges as "silly, laughable and guilt by association." Viguerie said he didn't know "anything about Moonism" and, if pressed, "would be hard put to name one or two people whom I know who are Moonies."

The Washington Times, in a scathing statement by its corporate executives, attacked Leach's "flummeries" and wrote off the Ripon Society as a "discredited and insignificant left-wing offshoot of the Republican Party."

"Anyone who has bothered to observe," the statement said, "knows by now that The Washington Times is at least as independent of its owners--operationally as well as editorially--as any corporately owned newspaper in the country."