A bipartisan group of mayors from around the country is preparing to send a letter to the House of Representatives urging it to debate and pass major gun control legislation.

The letter, addressed to Speaker J. Dennis Hastert (R-Ill.), urges the House to, among other things, pass provisions for raising the minimum age for purchasing and possessing a handgun from 18 to 21, requiring background checks at guns shows and limiting gun purchases to one a month per individual.

The Gun Violence Task Force of the U.S. Conference of Mayors -- meeting here for its 67th annual meeting -- approved sending the letter this morning. Its nine members include only one Republican, but other Republicans attending the meeting said they would sign the letter. Conference officials plan to circulate it this weekend for signatures among the 300 or so mayors in attendance. They said they would send it to Hastert on Monday.

"The time is ripe for meaningful change," said New Orleans Mayor Marc Morial (D). "We're engaged in a multi-front movement. In this letter, we are focusing on the U.S. House of Representatives. We want a bill with meaningful teeth."

The decision to send the letter came one day after Hastert announced that, because the GOP was so divided on the issue, the House leadership would let the process proceed without trying to "whip" members to back specific legislation.

Conference officials had not begun to circulate the letter this afternoon. Some mayors, particularly those from western and southern states, were not expected to sign it, but conference officials said they were certain that most would.

In a news conference after the task force's meeting, several mayors said the stark reality of the Littleton, Colo., school shooting has led Americans to reassess the issue of gun control and that public opinion is now squarely in favor of some basic restrictions.

The lack of partisanship here was in stark contrast to Washington. The conference is nonpartisan and the issue of party affiliation never came up during the task force's morning meeting.

"I live in a community that in the 1980s defeated a major gun control [referendum]," said Arlene J. Mulder (R), mayor of Arlington Heights, Ill. "But they are 100 percent behind having some sort of safety measures. The grass roots is really listening with these tragedies. Maybe it's time to listen to them."

Gary, Ind., Mayor Scott L. King (D) denounced Hastert's leadership on the issue, saying, "The speaker has thrown up his hands. It's ridiculous."

In a taped statement to the conference this afternoon, President Clinton echoed those sentiments, suggesting that "the House leadership seems intent on ignoring the lessons of Littleton." He chided House leaders for trying to "water down" a Senate-approved gun control measure. "So many issues like the gun issue . . . are not partisan issues anywhere in the United States except Washington, D.C.," Clinton said.

In Washington, Attorney General Janet Reno also tried to put pressure on the House to adopt legislation similar to the Senate measure, saying she was "very disappointed" in the proposed House version because it would "undermine the common-sense measures passed by the Senate to close the gun show loophole."

According to a Justice Department analysis, the Senate bill would require background checks of all gun buyers at any event where 50 or more firearms are for sale. But the House version of the bill would apply only to events "sponsored to foster the collecting or use of firearms" at which at least 10 vendors are selling firearms.

"It doesn't matter to criminals if the event is called a gun show or a flea market -- if they can buy guns without a [background] check, they will come," Reno said.

In an interview before a speech to the mayors this afternoon, Sen. John McCain (R-Ariz.) said that he thinks the city officials should send the letter because "they are the ones who are closest to the problem."

But later in his speech, McCain, who is running for the GOP presidential nomination, said gun control legislation alone would not solve the problem of violence among young people. He said officials and parents must muster the resolve to deal with cultural pollution in the media and on the Internet. "We can take away all of the guns, but I can still take you to the Internet and show you a site that shows you how to build a pipe bomb" or espouses hate or promotes pornography, McCain said.

Over the next five days, the mayors will take up a number of topics -- from education to health care, urban sprawl and federal mandates -- but none is likely to dominate the way guns and violence will. Vice President Gore will address both subjects when he speaks on Monday.

In recent years, big-city mayors have taken the lead in challenging gunmakers, with nearly two dozen cities, including New Orleans, filing lawsuits against the industry. The battle has been fierce in Louisiana, and today Gov. Mike Foster (R) signed legislation prohibiting cities from filing such lawsuits. Morial said the law would not be on the books long, not only because it would be struck down in court, but also because public sentiment would demand that it be overturned.

The gun control provisions demanded by the conference's task force -- including raising the minimum age for gun purchases and limiting gun purchases -- go beyond those in the House bill. "What we are talking about is getting guns out of the hands of our children," said Salt Lake City Mayor Deedee Corradini, president of the conference.

Staff writer Edward Walsh in Washington contributed to this report.

CAPTION: Salt Lake City Mayor Deedee Corradini, shown at Habitat for Humanity site, says, "What we are talking about is getting guns out of the hands of our children."