House Majority Leader Jim Wright (D-Tex.) said yesterday convicted Rep. Charles Diggs (D-Mich.) should not be expelled from the House if, after appeals, his conviction for taking salary kickbacks is upheld.

"I don't think he should be expelled from the House," Wright said. "Membership in the House is not ours to bestow. We can't give that to anybody. The constitutents are entitled to have the representatives of their own choice."

House Republicans recently announced they would ask the ethics committee to investigate grounds for expulsion and Democrats will consider a proposal concerning an expulsion vote at their next Democratic Caucus. The Congressional Black Caucus has announced it would oppose moves to expel Diggs and a bitter fight is expected, if the appeals process upholds Diggs' conviction.

At the same time, Wright predicted that Diggs would be denied the chairmanship of the African subcommittee on the International Relations Committee.

Wright also predicted that indicted Rep. Daniel J. Flood (D-Pa.), standing trial on bribery charges, would have a "difficult" time being reelected chairman of the Labor-HEW subcommittee of the Appropriations Committee.

Diggs must be nominated to the subcommittee post by the International Relations Committee. If he is renominated, it must be voted on by the Democratic Caucus because of a rules change adopted last month.

Flood's subcommittee chairmanship also is in the hands of the caucus, which clears appropriations subcommittee chairmanships.

Wright refused to say how he would vote in the caucus on the Diggs nomination, if it reaches the caucus. "That's not any of your business," Wright said, adding it was an internal matter of the House Pressed on whether such an issue was really an "internal matter" and whether as a leader he didn't have a responsibility to make his position known, Wright said, "I'm well within my rights as well as my responsibilities in keeping my vote secret."

Asked about a proposal that Diggs refrain from voting in committee and on the House floor until his appeals are exhausted, Wright said, "It's been their choice, their decision. I'll refrain from comment on that right now. I'm engaged in some conversations with some people on that."

There is a proposal by Rep. Peter Kostmayer (D-Pa.) scheduled for next week's caucus that a convicted member should abstain from voting until his appeals are exhausted or he has served his sentence or is cleared by the courts.

Wright noted that committee chairmanships are a privilege bestowed by the Democratic Caucus on House members and that members could properly revoke that privilege. But he said membership in the House is different. He said that he opposed excluding the late Adam Clayton Powell from the House, and noted that the House did not expel two convicted members, Andrew J. Hinshaw (R-Calif.), convicted in 1976, and J. Parnell Thomas (D-n.j./), convicted in the late 1940s for misuse of his clerk-hire allowance and receiving kickbacks from his employes.

Wright noted that only three persons had ever been expelled from the House, all in 1861 for the treason of joining the Confederacy. "We should be very, very careful before we expel someone who is constitutionally qualified," he said.

Wright noted that former Maryland governor Marvin Mandel's conviction was overturned on appeal, and warned against rendering "judgment" on Diggs.

Diggs was convicted on 29 counts of taking salary kickbacks from his staff and mail fraud. He was sentenced to three years and is appealing. Diggs gave up the chairmanship of the District Committee but wants to keep the chairmanship of the African subcommittee.

He abstained from voting last session after his conviction. He was reelected since the conviction, and House rules allow a convicted member who has been reelected to resume his normal duties.