Two of the Senate's least likely legislative partners, George McGovern (D-S.D.) and S. I. Hayakawa (R-Calif.), have been quietly discussing sponsoring a resolution to create a congressional delegation to monitor elections in Rhodesia in April.

The Carter administration opposes extending recognition to the elections scheduled unilaterally by the Salisbury government of Prime Minister Ian Smith. Agreement by the South Dakota liberal and the California conservative on a joint approach to Rhodesia could create new problems for the administration's beleaguered African policy.

The administration remains formally committed to the Anglo-American plan for a settlement between Smith's government and the African guerrilla forces of the Patriotic Front.

McGovern, who replaces defeated senator Dick Clark (D-Iowa) as head of the Africa subcommittee on the Foreign Relations Committee, gave the first sign of differences with the administration last month after he returned from Rhodesia and said the administration should admit the Anglo-American plan had failed.

Washington should also consider "disengaging" from its active diplomacy in Rhodesia and let the "long, bloody struggle" between the black nationalists and the Smith forces run its course, McGovern told reporters Dec. 21.

McGovern could not be reached yesterday for comment on his talks with Hayakawa. Conservatives on the committee appear to be eager to get the 1972 Democratic presidential nominee signed on for a resolution on Rhodesia, but McGovern apparently wants to proceed more slowly.

Staff assistants to Hayakawa confirmed the discussions but said no agreement had yet been reached between the two senators. These aides said that Hayakawa, who was out of Washington yesterday, felt that McGovern "has come a long way toward our position" on Rhodesia since his trip there.

Hayakawa is the ranking Republican on the Africa subcommittee, which will have a more conservative make-up this year than in the previous Congress. Clark, whose loss to a Republican was attributed by many observers to his generally liberal stance, was the strongest advocate in the Senate for the administration's Africa policy.

The State Department also has been informally advised of the discussions about a congressional delegation to observe the elections.

Under an amendment to the foreign security assistance bill last year, a determination by international observers that the elections are held freely and fairly is a key condition for the lifting of U.S. economic sanctions against the rebel British colony.

Kenneth Towsey, head of the Rhodesian Information Office in Washington, said that, while he had no guidance from Salisbury about a visit by a U.S. congressional delegation, he thought the proposal would be viewed positively by his government.

Hayakawa last year voted for the Helms amendment that would have lifted sanctions unconditionally, and he was a prime mover in the successful bid to get a visa for Smith to visit the United States last year.