Lawyers for Tongsun Park and the U.S. Justice Department agreed today that a threatened congressional subpoena of Park would not interfere with the agreement requiring his testimony in American courts on the influence-buying scandal.

"We don't intend to pull out the plug now," said Park's lawyer, William Hundley, in an interview as preparations began here for preliminary questioning of the South Korean businessman who is the central figure in the investigation.

At a news briefing later, acting U.S. Deputy Atty. Gen. Benjamin R. Civiletti said a House Ethics Committe threat to subpoena park when he comes to the Uniteed States presented no obstacle to obtaining Park's court testimony.

Hundley said that he thinks his client will agree to testify voluntarily before the House Ethics panel and two other committees. There would need to "clarification" of the Ethics Committee subpoena's terms, he said. "My guess is that it will be clarified," Hundley added. "We have got to know what they have in store for this guy."

Hundley said he would recommend to Park that he testify voluntarily in closed sessions and said he thought his client would heed that recommendation.

Park has been indicted for using South Korean money to attempt to influence U.S. congressmen on issues affecting South Korea. Under a Dec. 31 agreement, between the two countries, Park will be made available to testify in U.S. courts and he is promised immunity from prosecution so long as he testifies truthfully.

The House Ethics Committee has issued the subpoena to get its own direct information from Park. Last week, committee counsel Leon Jaworski said a failure by the South Korean government to help obtain Park's congressional testimony would "surely result in the most adverse consequences," a comment interpreted here as a threat to cut U.S. aid to Seoul.

In response, a high South Korean official - believe to be Foreign Minister Park Tong Chin - told the Seoul press that such a threat could block implementation of the Dec. 31 agreement.

The agreement specified that Tongsun Park was not obliged to testify before Congress. It left unanswered the question of whether he could be compelled to do so by congressional subpoena.

The South Korean official's remarks raised the possibility of either the government or Tongsun Park using the subpoena threat as a means of resisting compliance with the new agreement's requirement of court testimony.

The South Korean government has not said publicly whether it might try to balk on the agreement. A request for a clarification today has brought no reply.

U.S. officials said, however, that no government official of South Korea has indicated that the agreement might be in jeopardy and they seem inclined to write off the Seoul official's remarks as political posturing in response to Jaworski's threatening remarks.

Civiletti told reporters that Jaworski had known before he threatened retaliation against South Korea that "there were other cannels" available for obtaining Park's congressional testimony.The tentative offer of Park's voluntary testimony had been made earlier by Hundley of the Ethics Committee.

Meanwhile, preliminary preparations for interrogating Park here continued and Civiletti said the questioning could be Thursday.

Civiletti meets Tuesday with South Korean Vice Minister of Justice Lee Chong Won to discuss conditions for the questioning. Later in the day, he said, they would sign the formal mutual assistance prosecution agreement that calls for Park's questioning and court testimony.

On Wednesday, the two sides are tentatively scheduled to examine facilities where the questioning will take place - presumably a room in the Seoul district prosecutor's office. If all goes well, Civiletti said, he would then meet for the first time that day with Tongsun Park to sign a memorandum of understanding governing the interrrogation.

Civiletti said he expects the questioning to last 10 days. On his staff here is an FBI polygraph expert, Frank Connally, who will "periodically" administer lie-detector tests to Park. "I expect 100 per cent truth from Mr. Park on all relevant and material questions," Civiletti said.

He said he expects much new information from Parks interrogation on activities by congressmen that involve either ethical breaches or violations of law. "I think the interrogation will go very well," he said.

In the United States, Park could be called to testify in the trials of two other indicted men, former Rep. Richard Hann (D-Calif.) and Hancho Kim, a Korean-born businessman who is a naturalized American.

The questioning here will also seek to determine what Park knows about other alleged recipients of South Korean funds. He could be called to testify in U.S. courts in the trials of Hanna, Kim, or anyone else indicated in the case.

Park will not be guaranteed immunity and his indictment will not be dropped until he has completed testimony in all cases required in the judgment of U.S. prosecutors.