The Justice Department's civil rights chief leveled a scathing attack against Congress for exempting itself from civil rights laws and denied that he lied to senators last year about a Louisiana voter challenge case involving the Republican Party.

"It is almost laughable to sit here and listen to these grand protestations by members of Congress about this administration's civil rights rec-ord," William Bradford Reynolds told the Senate Judiciary Committee on Thursday.Referring to frequent complaints from liberals that the Reagan administration is trying to turn back the clock on civil rights, Reynolds said, "This chamber has not seen fit in over 200 years to reach out and even once wind the civil rights clock that watches in forced silence over its activities."

Congress has exempted itself from a myriad of civil rights laws dealing with discrimination in employment and other areas.

Senate Judiciary Committee members did not respond directly to Reynolds' comments, but Sen. Edward Kennedy, D-Mass., strongly criticized Reynolds for adopting a confrontational approach to dealing with civil rights issues.

Kennedy cited a Feb. 22 memo circulated in the Justice Department in which Reynolds said that "we must polarize the debate" in the waning months of the administration on issues ranging from AIDS to capital punishment to prison conditions.

"When it comes to civil rights under the Reagan administration, Reynolds is the name and polarization is the game," Kennedy said.

When Sen. Paul Simon, D-Ill., questioned whether polarizing the debate was "prudent," Reynolds replied that "I stole a page from your own book" and said Kennedy had been confrontational as well.

Reynolds is counselor to Attorney General Edwin Meese III as well as assistant attorney general in charge of the civil rights division.

Another judiciary committee member, Sen. Howard Metzenbaum, D-Ohio, accused Reynolds of lying last year and of rejecting subordinates' advice to launch an FBI investigation into a Republican Party voter registration challenge in Louisiana.

Metzenbaum disclosed memos by Reynolds' civil rights division subordinates urging that the FBI look into possible criminal violations of the Voting Rights Act in connection with a GOP voter registration challenge aimed at predominantly black precincts in Louisiana in 1986.

One memo to Reynolds, dated Oct. 7, 1986, from an attorney in the voting section, Rebecca Wertz, said that if the voter registration challenge were to be found to be a conspiracy to disenfranchise black voters, that would be a criminal violation of the Voting Rights Act. She noted that it is a crime punishable by up to five years in prison to deprive anybody of a right under the voting act.

In March 1987, Reynolds told the committee that it was the conclusion of "everybody who looked at the matter" from the division's voting section that "there was no . . . violation of the Voting Rights Act that would allow us to go in and prosecute."

"You misstated the facts; you lied to the committee," Metzenbaum told Reynolds, who responded that Metzenbaum was stating "half-truths."

Reynolds said that another part of the Justice Department, the criminal division, was consulted on the matter and concluded that no criminal investigation was warranted.

Reynolds and a deputy, Jim Turner, insisted that subordinates in the civil rights division ended up agreeing that no FBI probe was needed.

Since the case involved the Republican Party, "I wanted to be darn sure I wasn't going to do something they would question us about later," Reynolds said.