Riding a wave of voter concern about violent crime, House Republicans and conservative Democrats rebelled against the House leadership yesterday and blocked debate on a major new crime bill they charged would prevent states from executing more criminals.

By a 258 to 166 vote, the House refused to take up the bill under a leadership-imposed "modified rule" that barred some amendments aimed at limiting the appeal rights of death row inmates. House Judiciary Committee leaders promised to try to bring the bill back with a more open rule, but expressed fears that anti-crime sentiment was sweeping the House and overcoming reasoned debate on the issue.

"It's more perception than anything," said Rep. William J. Hughes (D-N.J.), chairman of the Judiciary subcommittee on crime, explaining the vote. "Anything that sounds like it might be tougher -- whether it is tougher or fair -- has a good chance of carrying the day."

The action came while law enforcement groups were attacking the Democratic leadership's handling of the measure on other grounds. On Monday, the Rules Committee refused to permit debate on an amendment requiring a seven-day waiting period on handgun sales to allow background checks of prospective purchasers, a top priority of major police groups.

Dewey Stokes, president of the Fraternal Order of Police, charged that House Speaker Thomas S. Foley (D-Wash.) was "directly responsible" for holding the waiting period measure "hostage," with the backing of the National Rifle Association. "Should we wait until the blood of law enforcement officers and of citizens runs into the floors of Congress until we pass a piece of sensible legislation?" Stokes said at a news conference called by law enforcement organizations.

Jeffrey R. Biggs, a spokesman for Foley, said the speaker was not blocking any House vote on the measure. But with the press of business in the final weeks of this session, a vote on it "cannot be guaranteed," he said.

Every even-number year since 1984, Congress has enacted major crime or drug bills -- an election-year ritual that civil liberties groups charge has chipped away at constitutional protections for criminal suspects. This year's measure, however, appeared somewhat different: While the 352-page House Judiciary Committee bill adds crimes for which the death penalty could be imposed -- including assassination of a member of Congress -- and streamlines court handling of death penalty appeals, it also includes controversial provisions backed by the American Civil Liberties Union designed to protect defendants' rights.

One such provision is a new "racial justice" law that would block executions if it can be shown statistically that they are being used disproportionately against minorities in particular states. Other sections would require states to provide "competent" counsel to defendants accused of murder, and would overturn a 1989 Supreme Court decision sharply restricting the ability of state prisoners to challenge their sentences in federal courts.

Two weeks ago, Attorney General Dick Thornburgh called the measure "pro-criminal" and President Bush said he would veto it on grounds it "handcuffs the police." Those comments were echoed on the House floor yesterday, with Republicans, led by Rep. Henry J. Hyde (Ill.), saying the crime bill would effectively "do away" with the death penalty.