A Virginia House committee, rebuffing pleas from black legislators and civil rights leaders, today killed a bill to create a state holiday honoring Martin Luther King Jr.

The 13-to-7 vote--with eight Republicans joining five Democrats in opposition--came after an emotional three-hour hearing in which the slain civil rights leader was alternately praised by supporters as a beloved hero to black America and denounced by an assortment of critics as a communist-inspired agitator.

In a virtual rerun of last year when the House General Laws Committee also killed a similar bill, black leaders angrily promised political reprisals against those who opposed them.

"Where we can have a piece of your hide, we will take it," said Jack Gravely, director of the state NAACP. "This is not a threat, this is the democratic process."

Gravely's words, however, infuriated committee members, at least one of whom, Del. Warren E. Barry (R-Fairfax) said he switched his vote because of them. "I was going to abstain," Barry said, but since Gravely raised political factors, he decided to vote against the bill because "I got 197 pieces of mail and they were all opposed."

During the past three years, the King bill has taken on growing symbolic importance to black leaders, who have frequently cited it as a litmus test of political sensitivity to their concerns. Two years ago the bill cleared the General Assembly only to be vetoed by former Gov. John N. Dalton, a Republican.

Today's vote was a crushing blow to the bill's backers, not only because it lost by a greater margin than last year, but because Democratic Gov. Charles S. Robb, who had criticized Dalton, made little effort to support them.

At a meeting with the bill's chief sponsor, Sen. L. Douglas Wilder (D-Richmond) Tuesday, Robb was urged to lobby committee members for the measure, which had already passed the Senate. Robb dispatched a lukewarm letter to Wilder promising that if the King bill passed the General Assembly, he would sign it.

He would do so, Robb added, "with the full understanding many non-black Virginians would probably choose to have Virginia honor the memory of one of its own distinguished sons and daughters, black or white, before the Commonwealth looked beyond its borders."

Wilder, a close political ally of Robb's, was reluctant to criticize the governor after the vote, but noted that he declined to open the letter when it was hand-delivered today by Robb aide Ben Dendy. "I did not consider the letter as something I wanted to use as evidence before the committee," Wilder said.

"I think the governor could have done more, he could have twisted some arms," said Michael Brown, also of the NAACP. "I'm somewhat disappointed."

More than 200 people, most of them supporters, packed the committee room for today's hearing, but most of the attention was grabbed by a handful of perennial opponents who each year turn up at the General Assembly to attack King. One woman said she had been collecting data on King for the past 18 years proving that he associated with communists, and a man from suburban Richmond said King's goal was to dilute "the white race" through "mongrelization."

"This just makes me sick to my stomach," commented Gordon C. Morse, director of Common Cause. "We just have this annual thing that just brings out the worst aspects of the state's history. It's just appalling."