Members and staff aides of the House ethics committee pledged yesterday they would remain with their investigation of the South Korean influence-buying scandal despite the abrupt resignation of the committee's special counsel, Philip A. Lacovara.

But a growing number of Republicans and junior Democrats in the House complained that the flare-up between Lacovara and the committee chairman, Rep. John J. Flynt Jr. (D-Ga), proved that Flynt's committee cannot be relied upon to pursue the Korean matter effectively.

Lacovara added support to those critics in a telephone interview from London.He said he had "grave doubts whether any investigation can succeed under the present leadership of the committee."

Lacovara recommended yesterday that the House set up a "commission of inquiry" independent of the ethics committee and the House leadership.

Committee members unhappily agreed that Lacovara's departure would delay the investigation, which has already been criticized for its sluggish pace. Staff investigators said the development would probably exacerbate their somewhat frosty relations with the Justice Department which is carrying on its own investigation.

"Phil had been getting to a point where we had fairly good cooperation from Justice -- getting information we needed," said Jeffery Harris, the committee's deputy chief counsel. "Now they'll be even more circumspect around us."

Lacovara 34, severed his law firm's contract with the ethics committee Friday evening after Flynt publicly criticized him and questioned the validity of his legal fees.

Flynt personally had hired Lacovara because of the experience and reputation the attorney had acquired on the Watergate special prosecution force. But the chairman and the special counsel never got along with each other committee members said.

"The chairman is very protective of his authority." Rep. Millicent Fenwick (R.N.J.) explained yesterday. "Mr. Lacovara was equally assertive. It was a severe clash of personalities."

House Republican Whip Robert Michel [Word Illegible] suggested that politics rather than personalities was responsible for the ethics committee's difficulties.

Noting that most of those linked so far to the alleged Korean bribery attempts have been Democrats. Michel said the committee has been "footeragging."

"I guess too many people of importance are involved," Michel said.

Lacovara's sudden departure prompted more calls for President Carter to appoint a special prosecutor to investigate the Korean connection. That demand came from Republicans in both houses of Congress and from a group of 35 junior Democrats in the House.

The Carter administration has rejected such requests on grounds that the Justice Department's ongoing investigation -- centered in the department's Criminal Division -- is independent of the House committee's probe and is free of political influence.

At his home in Griffin, Ga., according to news reports, Flynt said he would quickly hire a new special counsel to continue the committee's investigation.

But committee members and staff aides questioned whether any lawyer of stature would accept theposition after Lacovara's experience.

"I'm very, very worried," said Rep. Fenwick. "I don't see how we can get anybody to run this investigation now. I don't know what's going to happen."

Lacovara said yesterday "From my experience, I can't imagine anybody getting a suitable arrangement if he is working under a committee chairman.

Lacovara is in London on a "working vacation," he said. Although he made the trip mainly for a rest, he said, he also had tried to contact Tongsun Park, the South Korean who left Washington for London when the investigation was beginning.

Lacovara said he had reached Park, but that Park refused to talk at all about his dealings in the United States.

Investigator Harris said he and other staff members intended to stay "at least until we find out whether we can continue a professional investigation."

"We want to ferred out the facts, Harris said. "Based on what I've already seen, boy! I'd sure like to follow this." CAPTION: Picture, Portion of 1970 Park ledger lists "5-Hanna, 5-Minshall" item, total $10,000