Sen. George McGovern (D-S.D.) said yesterday that he has recommended to Secretary of State Cyrus Vance that an impartial team of professional observers be sent to monitor the disputed elections sheduled for April in Rhodesia.

The observers would report to President Carter, who is required by legislation passed last year to make a determination on the legality of a national election in Rhodesia as a condition for lifting U.S. economic sanctions against Rhodesia.

A press release issued by McGovern emphasized his continuing differences over Rhodesia with Sen. S. I. Hayakawa (R-Calif.), the ranking Republican member on the Senate's Africa subcommittee wiich McGovern now heads. The release confirmed that the two senators have been discussing an observer force, as reported yesterday by The Washington Post.

McGovern said he opposes making members of Congress part of an observer force. "Congress with its sharp divisions on the Rhodesian issue and its heavy workload is not capable of providing from its membership an impartial observer force." A congressional delegation of observers "would be a political farce," he said.

McGovern also emphasized that he opposes the lifting of sanctions "unless there has been a full and good faith effort in Rhodesia to establish majority rule by an all parties conference and a legitimate nationwide election." Hayakawa voted last year for an unsuccessful attempt to lift sanctions unconditionally.

Critics of the plan by Prime Minister Ian Smith's Salisbury government to hold unilateral elections point out that more than half of Rhodesia's territory is currently under martial law. They assert that free and fair elections are impossible while the war between Smith's white-dominated army and the African guerrillas of the Patriotic Front continues.

The State Department is studying McGovern's suggestion on an observer force, according to the State Department's press office.