Democrats and Republicans on the Iran-contra panels chastised Assistant Secretary of State Elliott Abrams yesterday for his role in secret administration efforts to aid the Nicaraguan contras, with some saying his credibility was so damaged that he no longer could act as an effective salesman for renewed contra aid.

Senate Select Intelligence Committee Chairman David L. Boren (D-Okla.), a contra aid supporter, said there is "too much in the record" for Abrams "to be able to effectively play" a role in rebuilding trust between Congress and the administration on Central American policy. The intelligence panel plays a major role in overseeing the contra program.

But Abrams, who yesterday completed nearly 10 hours of testimony over two days, vowed to stay on the job as assistant secretary for inter-American affairs and said that he is "very proud" that he still has the complete support of Secretary of State George P. Shultz.

State Department spokesman Charles E. Redman said yesterday that Shultz believes that Abrams has done a "sensational job" and has "full and complete confidence" in him.

Rep. William S. Broomfield (R-Mich.), who praised Abrams during the hearings, said after yesterday's hearing it is clear that "Elliott has problems with key members of Congress."

Broomfield said he was not suggesting that Abrams resign "at the present time," but added there was "no question" that Abrams would have difficulty continuing to serve as the administration's chief lobbyist in this year's battle over renewed aid for the contras fighting the government of Nicaragua.

Abrams lived up to his reputation as a combative and forceful speaker during intensive questioning and was quick to dispute what he called "erroneous" attempts by some panel members to attach devious or sinister interpretations to his actions.

Abrams did not offer any personal apologies for his conduct, but, echoing earlier testimony by former national security adviser Robert C. McFarlane, conceded that the administration's support of the private contra aid network was a "dangerous policy" and soliciting money from foreign governments "is not the way a great nation should run its foreign policy."

Abrams reluctantly agreed that he was betrayed by fired National Security Council aide Lt. Col. Oliver L. North and others, who never advised him to stop denying that the government was involved in the private network aiding the contras.

But Abrams did not agree with some committee members who said he was one of the administration's "designated fall guys."

"It is not {Shultz's} view, nor is it my view that I am the fall guy," Abrams told Sen. George J. Mitchell (D-Maine). "I am, and plan to be, assistant secretary of state for inter-American affairs."

Committee members repeatedly ripped into Abrams, the administration's "point man" on contra aid since July 1985, for misleading Congress about the administration's secret efforts to keep the contras alive during a two-year ban on U.S. military aid.

In particular, committee members hammered at Abrams for providing what turned out to be repeated inaccurate statements last fall to congressional committees and to the public in which he denied that the U.S. government had any role in a contra air resupply operation.

In fact, testimony before the panels has established that North, who was fired last November from the NSC staff for his role in the Iran-contra affair, helped organize and direct the private air operation, which was exposed last Oct. 5 when a C123K cargo plane was shot down over Nicaragua.

Abrams also was criticized for not telling the Senate intelligence panel last Nov. 25 that the administration had solicited a $10 million donation for the contras from the sultan of Brunei. Abrams traveled to London last August, and using a fake name, "Mr. Kenilworth," personally solicited the $10 million from a Brunei official.

Abrams told the panel that when the intelligence committee asked him about possible administration solicitations of foreign governments he did not reveal the Brunei incident because Shultz had not authorized him to do so.

"That's the most cockamamie idea I ever heard," Rep. Jack Brooks (D-Tex.) said.

Brooks challenged Abrams' assertions that he was only generally aware of private efforts to support the contras and of North's role in that program.

"You seem to be proud about not knowing anything of the technical problems and the real sticky problems with which you are involved," Brooks said. " . . . I can only conclude that you are either extremely incompetent or that you are still, as I say, deceiving us with semantics, or . . . that the administration has intentionally kept you in the dark so that you could come down and blatantly mislead us . . . . I am deeply troubled by it, and wonder if you can survive as assistant secretary of state."

Sen. Warren B. Rudman (R-N.H.), the Senate panel's vice chairman, told Abrams that he displayed an "incomprehensible lack of curiosity" when Abrams did not press North about a possible U.S. role in the contra air resupply operation. "I mean knowing Elliott Abrams as I think I know him, I would think Elliott would have gone down there and raised the devil," Rudman said.

"Now we know what I should have done," Abrams told Rudman. "But . . . I didn't know any of this. And now it's all come out, and it's really rather incredible. And it keeps getting more incredible as the days go by and as more evidence comes out."

Panel members also noted that Abrams' testimony differs sharply with accounts offered by other witnesses, including retired Army major general John K. Singlaub, a key private contra aid supporter, and Lewis A. Tambs, former U.S. ambassador to Costa Rica.

"I don't know whether to believe you or Gen. Singlaub, to believe you or Ambassador Tambs," said Sen. Daniel K. Inouye (D-Hawaii), chairman of the Senate panel. "It's not my job to decide whether you or the other one is honest. But someone is not being honest with us."