Defiant Republicans on both sides of the Capitol began laying the groundwork this weekend for an effort to force a bipartisan group of Senate negotiators to accept key changes to the intelligence reform bill or see the legislation die for the year.

With the House returning to Washington on Monday, it appeared that Speaker Dennis Hastert (R-Ill.) and other House Republican leaders had not yet been convinced to abandon their policy of seeking a “majority of the majority” before voting on the conference report, which would implement the 9/11 commission’s recommendations. In addition, the emergence of new opposition in the Senate indicated the need to change the bill before calling it up for a possible vote this week.

“The bill is not going to be passed unless the conference [report] is opened,” said one knowledgeable Senate GOP aide.

Meanwhile, the White House and Congressional backers of the Pentagon continued talks designed to find a solution that would assuage the concerns of House Armed Services Chairman Duncan Hunter (R-Calif.) and still get majority support of Senate conferees, who have been cool to reopening the months-long negotiations.

Hunter has complained that the conference report, which would create a new director of national intelligence, could prevent soldiers from getting timely intelligence on the battlefield. He has fought for changes to the bill that would “protect the military chain of command.”

Hunter spokesman Harald Stavenas said in a statement, “We are hopeful to get something hammered out soon.”

Both the House and Senate will be in session this week, and House Republicans are expected to gather Monday to decide whether to bring the measure up for a vote.

The bill still appears to have the support of a majority of both chambers, and President Bush used his weekly radio address Saturday to refute Hunter’s claims and call for passage of the conference report. However, the bill has been in limbo since Hastert declined to bring the measure up after Hunter convinced many rank-and-file Republicans on Nov. 20 to oppose the House-Senate negotiated conference report.

House Judiciary Chairman James Sensenbrenner (R-Wis.) also opposes the bill, based on its exclusion of language prohibiting states from issuing drivers’ licenses to illegal aliens, among other controversial immigration provisions.

Hastert has come under increased pressure to ignore Hunter’s and Sensenbrenner‘s concerns, using the overwhelming support of House Democrats to help carry the bill to passage.

But this weekend, Hastert got some needed support as even seemingly stalwart backers of the Bush administration defended Hunter and Sensenbrenner and called for their concerns to be addressed by reopening the bill.

“I do believe [the bill] can be improved, and I don’t think we should ignore two important chairmen,” Senate Judiciary Chairman Orrin Hatch (R-Utah) said on CNN’s “Late Edition.” “I hope there can be a compromise, and I think there probably has to be.”

Hatch went on to say that the president has already implemented the most needed of intelligence reforms by executive order. “I don’t think Osama bin Laden will be quaking in his boots because we do or do not pass this bill,” he said.

Rep. Mike Pence (R-Ind.), a Deputy Majority Whip, said the president’s radio address would have little impact on whether House Republican leaders bring up the bill unchanged.

“While the Pentagon has to fall in when the president gives an order, the Congress does not have an obligation to fall in when the commander and chief gives an order,” said Pence on CNN’s “Inside Politics.” “It’s our job to deliberate, to create a product that will see to the best interest of our armed services and the protection of our citizens.”

Across the Capitol, Senate Armed Services Chairman John Warner (R-Va.) aligned himself with Hunter on Friday, giving momentum to Hunter’s push to change the bill. Warner has been exchanging proposed language with the White House in an attempt to broker a compromise.

But Senate Governmental Affairs Chairwoman Susan Collins (R-Maine) and ranking member Joseph Lieberman (D-Conn.), the Senate’s leader negotiators on the measure, have both dismissed as unnecessary attempts to reopen the bill, stopping short of an outright refusal.

“We’ve got the votes. We’ve always had the votes. It’s up to the Speaker to bring it up,” said one senior Senate GOP aide whose boss supports the conference report.

Still, Collins spokeswoman Jen Burita noted that, “Senator Collins is continuing to work with the White House and Congressional negotiators.”

But Stavenas disputed the notion that the bill would not have problems passing the Senate.

“We don’t expect the rest of the Senate to rubberstamp the conference report. Democratic and Republican Senators have explicitly told conferees they will not sign off without due consideration” for Hunter’s views, Stavenas said.

In addition, Senate Select Intelligence Chairman Pat Roberts (R-Kan.) a strong backer of the conference report as currently drafted acknowledged that the bill may not pass this week given the continuing impasse.

“If it doesn’t pass this next week, we will have to start all over again in the next session because it’s that important,” Roberts said on CBS’ “Face the Nation.”