The House is expected to vote today on carrying out its threat to cut aid to South Korea because of what may be a final breakdown in negotiations to question a Korean diplomat suspected of paying off House members.

Congressional sources said that the final rebuff from the Korean government came yesterday despite concessions by Leon Jaworski, special counsel to the House Committee on Standards of Officials Conduct, that former ambassador Kim Dong Jo wouldn't be required to give sworn testimony.

Meanwhile, the committee deliberated for six hours yesterday without reaching final decisions on whether to start disciplinary proceedings against a handful of members who took cash from another Korean, accused agent Tongsun Park. The committee meets again today.

The House approved a non-binding resolution last month threatening to cut off nonmilitary aid to the South Koreans if they didn't cooperate in providing information about payments Kim allegedly made to as many as 10 current members of Congress.

Members of the House leadership made it clear then that they would push for the aid cutoff if some arrangement on Kim wasn't made. And the vehicle for the cut is the agricultural appropriations bill, which the House is to consider today.

Gary Hymel, executive assistant to House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.), said last night that an amendment would be offered prohibiting expenditure of the $56 million earmarked for Food for Peace aid to South Korea.

O'Neill will support Jaworski's position - and thus the amendment - as he has consistently in the past, Hymel said.

Majority Leader Jim Wright (D-Tex.) is prepared to sponsor the amendment, sources said.

The investigating committee took "tentative action" or "straw votes" on some of the cases before them yesterday, members said after the all-day meeting. No final action was taken because the members are wrestling with language to attach to recommended penalties in the few cases expected, several said.