House Democrats, arguing that their integrity was at stake, yesterday voted by better than 2 to one to strip Rep. Robert L.F. Sikes (D-Fla.) of the chairmanship of the Military Construction Appropriations Subcommittee.

After the Democratic Caucus vote of 189 to 93, Sikes said, "I'm still a member of the Congress. I respect the oath I took. I expect to be the best member of Congress God gives me the strength to be."

Sikes had been reprimanded by the House ethics committee and the House 381 to 3 last year.

He becomes the only chairman to be ousted by House Democrats in this Congress. Two years ago they ousted three.

Sikes was reprimanded for ethics violations that included failing to disclose stock holdings in Fairchild Industries, a defense contractor; promoting the establishment of the First Navy Bank at the Pensacola Naval Air Station, then becoming the third-largest stockholder in the bank and sponsoring legislation to allow development of Florida property in which he had a substantial financial interest. The last action, the ethics committee report said, "created an obvious and significant conflict of interest.

Sikes' opponents argued yesterday that the integrity and credibility of the House were at stake.

"This is the moment for the Democratic Caucus to determine if in fact we are capable of disciplining ourselves," Rep. Butler Derrick (D-S.C.) said.

Rep. Richardson Preyer (D-S.C.), who is to head a new committee to write into law a tougher code of ethics, said, "The ultimate test of a code is whether it can be enforced. If it's not enforced, it's a futile exercise no matter how strong it is."

"I believe Rep. Sikes had a conflict of interest and concealed it from his colleagues and the country," Rep. Richard Bolling (D-Mo.) said, "We would be ill advised to give our power to a man who has done that."

Though House Speaker Thomas P. (Tip) O'Neill and Majority Leader Jim Wright (D-Tex.) had announced they would vote for Sikes, no powerful House member defended him with the exception of Rep. John Flyntt (D-Ga.). He is chairman of the House ethics committee, which last year recommended that Sikes be reprimanded.

"I know of no action taken by a committee which I chaired, I know of no action taken by the House which found Sikes guilty of a conflict of interest," Flynt said.

He argued that Sikes had been tried and judged and yeaterday's action was putting Sikes in double jeopardy.

Another Sikes defender, Rep. Sam Stratton (D-N.Y.), said, "I hope we're not proceeding against Sikes because he stood up for a strong defense." Rep. John Dent (D-Pa), said "I can give you a list of violations 10 feet long by other members."

Rep. Andrew Maguire (D-N.Y.), who sponsored letters asking the ethcis committee to investigate Sikes and more recently urging his ouster, said he was surprised at the margin of the vote.

"I thought we'd win by 20 votes," he said. Maguire called it "unfortunate" that O'Neil had endorsed Sikes, but Maguire added, "how himslef came to that conclusion because he made it abundantly clear later that we should vote as we saw it, it was not a leadership issue, and that helped us."

However, Common Cause president John Gardner said, "The Sikes rejection is a major defeat for the new Democratic leadership of the House." Common Cause had urged that Sikes be investigated.

But O'Neill said, "It's no defeat for the leadership. It was obvious to all of us Sikes had no chance," O'Neill said he knew the vote would be that overwhelming and added. "Close friends (of Sikes) asked me to get him to withdraw from the race, but I didn't think it was any business of mine."

O'Neill reaffirmed his pledge to write a strong code of ethics and said he would welcome Gardner's help in getting it adopted. "I hope he has as much clout as he believes he has," O'Neill said.

Naguire also criticized ethics Chairman Flynt, saying it was "astonishing" Flynt would defend a man his committee acted against. "He's been compromised very seriously in my judgement," Naguire said.

Another Democrat said, "Flynt has single-handedly managed to give the ethics committee another black eye and call its credibility on the Korean investigation into question." The ethcis committee is scheduled to shortly begin an investigation into South Korean nationals' attempts to buy influence with members of Congress.

Many of Sikes' opponents argued that the sincerity of wanting to write a new code of ethics would be called into question if Sikes were not reprimanded for violating the old code. "Now we have a 2-to-1 mandate to implement that new code," Maguire said.

Late yesterday, the Appropirations Committee met and nominated Rep. Gunn McKay (D-Utah) to chair the Military Construction Subcommittee, which doles out $3 billion a year for construction and maintenance on military bases. The caucus will vote today on McKay and little or no opposition is expected.

Though all standing committee chairmen must stand for election every two years, the Appropriations Committee is the only committee required to have its subcommittee chairmen elected by the Democratic Caucus.