Only a day after rallying Republicans behind a common agenda, House Speaker J. Dennis Hastert (R-Ill.) found himself struggling to salvage his initiatives on gun control, an issue that has haunted his party since the mass shootings in Littleton, Colo., in April.

Moderate Republicans, Democrats and President Clinton all voiced disappointment yesterday over a new package of House GOP gun control measures -- drafted with the input of the National Rifle Association -- that would weaken Senate-approved mandatory background checks for all firearms purchases at gun shows.

Even more troubling for Hastert, his two top lieutenants, Majority Leader Richard K. Armey (R-Tex.) and Majority Whip Tom DeLay (R-Tex.), are siding with gun control opponents against much of the speaker's plan.

"In my district they have a saying: `Cut my taxes and leave my guns alone,' " Armey said in an interview. "That pretty much says it all."

Such comments bode ill for Hastert's hopes of avoiding the kind of divisive debate over gun control that took place in the Senate, where the GOP leadership was forced to make an embarrassing series of concessions to Democrats. It also raised questions of whether even the modest anti-gun measures approved in the Senate would emerge from the House -- and whether Republicans could outmaneuver Democrats on an issue some lawmakers say could be potent at the polls next year.

"I'm very disappointed," said Rep. Marge Roukema (R-N.J.), a gun control advocate. "It looks as though we learned nothing from the Senate debacle and we'll have a political backlash."

In addition to mandatory background checks at gun shows, the Senate bill approved last month would require safety locks to be sold with new guns and would ban the importation of high-capacity ammunition clips.

Hastert has embraced those general provisions, but bill language unveiled by the House GOP this week would alter the Senate bill in several important ways, including narrowing the range of gun shows where background checks must be conducted. The new proposals, scheduled to come to the floor next week as part of a juvenile justice bill, also include controversial measures to limit depictions of violence in the entertainment media.

While Democrats and some moderate Republicans complained the gun changes essentially gut the bill, conservative Republicans said there is little enthusiasm even for modest gun controls and said Hastert had misread the mood of his caucus.

"He got out of the gate early . . . not understanding where his conference was as a whole," a senior House GOP aide said of Hastert. "This is a pro-gun conference. Hastert has placed himself on an island."

In a brief interview, Hastert dismissed questions about GOP divisiveness over the issue as "speculation," adding, "I just don't know everyone's views."

Rep. Barney Frank (D-Mass.) said the speaker's efforts to push through his measures next week, over the objections of many in both parties and without review by the House Judiciary Committee, "certainly adds to the `Republicans in disarray' theme."

Clinton charged yesterday that the House leadership was attempting to push through a dramatically watered-down version of the Senate-passed bill "plainly ghost-written by the NRA."

"I think it is wrong to let the NRA call the shots on this issue," Clinton said. "This is a classic, horrible example of how Washington is out of touch with the rest of America, and it is time that the rest of America corrected it."

House Judiciary Committee Chairman Henry J. Hyde (R-Ill.), a longtime gun control supporter who has worked in concert with Hastert to draft the proposals, dismissed Clinton's comments as "nonsense." He said the plan is aimed at expanding the number of background checks conducted.

"We're trying to adopt a law that closes the loopholes," Hyde said, adding that NRA officials made their views known to his staff but did not have access to the bill. "The NRA is a legitimate organization. They have an interest in the subject."

The internal GOP debate comes at a time when House leaders are trying to strike a balance between gun control opponents, which include the majority of Republicans and a small but important group of Democrats, and gun safety advocates among moderate Republicans and liberal Democrats.

"We're just struggling to find the middle ground as a party," said Bill McInturff, a Republican political consultant."

In a meeting with Judiciary Committee Republicans yesterday morning, for example, several lawmakers told Hyde they could not support his plan to impose a 72-hour background check at gun shows and prohibit the sale of handguns to anyone under 21.

"We have great respect for the chairman, but probably a lot of us in the Judiciary Committee have pretty pro-gun districts," said Rep. Edward G. Bryant (R-Tenn.). "We're all under severe pressure from our districts to protect against any additional burdens on law-abiding gun owners."

Other GOP lawmakers outside the committee share this view. Rep. Wally Herger (R-Calif.) said that calls in his district have been running 11 to 1 against further gun control and that he was "inclined" to resist any new safety measures.

Moderate Republicans, meanwhile, have been riled by the Hastert-Hyde measures and are urging the speaker to open up the floor debate next week to amendments that would close what they see as loopholes.

Currently, licensed firearms dealers must run background checks on purchasers, whether at a gun show or at a store. But the more informal unlicensed vendors at the shows aren't required to run those checks, a loophole that critics say has made it easy for criminals, minors and others who might otherwise be ineligible to buy guns. Whereas the Senate-passed version defines a gun show as any event at which more than 50 guns are for sale, the House version regulates only events at which 10 or more vendors are selling guns.

CAPTION: Reps. Carolyn B. Maloney (D-N.Y.) and William J. Pascrell Jr. (D-N.J.) display "smart gun" with electronic technology.