Congress yesterday canceled its usual January recess as anxious lawmakers prepared for a full-scale debate later this month on whether to authorize the use of U.S. military force to drive Iraq out of Kuwait.

The Persian Gulf conflict dominated the formal opening of the 102nd Congress, forcing all other issues onto the sidelines in what appeared to be the start of a difficult search for consensus on whether the country should go to war.

In early-morning meetings with President Bush, Democratic leaders told the president he cannot order combat without congressional authorization and flatly rejected his earlier suggestion of an immediate grant of authority for offensive military action.

They welcomed Bush's proposal that Secretary of State James A. Baker III meet with Iraqi Foreign Minister Tariq Aziz next week in Switzerland and agreed to hold off debate until after Baker returns. But the congressional leadership quickly ran into objections from two Senate Democrats who protested any delay in the beginning of deliberations on the issue.

Only six minutes after the Senate finished swearing in new members, Sen. Tom Harkin (D-Iowa), with the support of Sen. Brock Adams (D-Wash.), tried to force debate on a resolution that would prohibit Bush from attacking Iraq without "explicit authorization" from Congress.

Senate Majority Leader George J. Mitchell (D-Maine) had hoped to block such moves with a resolution limiting introduction of bills and resolutions until Jan. 23, when Congress originally had been scheduled to reconvene. But Harkin and Adams thwarted Mitchell's plan by threatening to deny him the unanimous consent necessary for approval of such parliamentary moves.

"These are not normal times . . . American men and women may be dying in combat" and Congress should debate whether to go to war before it starts rather than after, Harkin told the Senate.

Mitchell, who appeared surprised and angered by Harkin's move, said Congress would have full opportunity for debate after results of Baker's mission are known and warned colleagues against an out-of-control debate that could undermine Baker's efforts to reach a peaceful solution to the conflict.

Senate Democrats tried to reach a compromise on how to handle Harkin's resolution but broke up in early evening without an agreement. They plan to continue trying to work it out today.

"We're all mixed up," said Senate Minority Leader Robert J. Dole (R-Kan.), who joined in the leadership's support for a delay in debate. "When we should have been debating, we were on vacation. Now that we should be quiet, we want to vote."

Bush and Democratic leaders have been at odds for weeks over whether the president can order troops into combat without authorization from Congress and appeared to make no headway in resolving the dispute yesterday, raising the potential for a constitutional confrontation.

"I don't believe we've persuaded him of our view, and I know he did not persuade us of his view," Mitchell said after the meeting at the White House.

Rep. David R. Obey (D-Wis.) went further, saying he thought it was an "impeachable offense" to order offensive military operations without a declaration of war. "It's a gross disservice to the people in uniform to go into war without an explicit declaration of war," Obey added.

House Majority Leader Richard A. Gephardt (D-Mo.) came out of the White House meeting yesterday with the view that Bush "leans to the side that says you go {to war} sooner rather than later."

"I think the president wants and intends and is ready to use force and wants to go forward," Gephardt said. "I think the Congress has to be involved in that decision, has to vote on that decision. I think that's what the Constitution contemplates, and from a political viewpoint, I think that's what we need."

House Speaker Thomas S. Foley (D-Wash.) rejected suggestions that Congress is putting off debate because it wants to have it both ways on the Persian Gulf issue and to avoid the appearance of division. "I don't think there's any question that we're going to go on the record at some time. . . . The question is what is the best time for that debate to take place," he said.

Foley and Mitchell dodged questions about what kind of resolution they might support, saying they wanted to await the results of Baker's trip. But they reiterated in strong terms that they were unwilling to go along with a suggestion from Bush for immediate approval by Congress of a resolution similar to the United Nations's call for use of all appropriate means to get Iraq out of Kuwait.

Prompt passage of such a resolution would be neither possible nor wise, Mitchell said.

"If we now say in the United States that the president has the authority at some unspecified future time, any time of his choice in the future under some as yet undefined circumstance, to initiate war, then how is the United States different from a monarchy or a dictatorship. . . ?" Mitchell asked in one of several televised interviews before the White House meeting.

But while Bush said he would like an affirmative vote from Congress supporting the U.N. resolutions, the White House repeated its view that at present it prefers no vote by Congress to a contentious debate that might signal disunity to Baghdad.

"If Congress wants to endorse the United Nations resolutions, and the president's responsibility to carry out their thrust, he would be very happy," White House Chief of Staff John H. Sununu said. "If they want to stand up and be counted, he would be very happy. But if all they want to do is enter into an extended debate without a result, it would be counterproductive."

White House press secretary Marlin Fitzwater said Bush would continue his consultations with Congress and would meet his constitutional obligations. "There's been no decision to use force. . . ," Fitzwater said. "We understand the constitutional responsibilities and we'll meet them. But that's as far as we intend to go."

Fitzwater said Bush has broad public and congressional support for his gulf policy, but added that there was a clear disagreement on when to use force.

While many members of Congress have urged Bush to give the economic sanctions more time to work, Fitzwater said the administration had "already concluded that the sanctions probably are not going to, by themselves, drive {Iraqi President} Saddam {Hussein} out of Kuwait."

Preliminary results of a Washington Post-ABC News Poll suggest that about seven out of 10 Americans believe that Congress should be more actively supporting the Bush administration's policies in the Persian Gulf. Only about one out of six say Congress should be more critical.

Interviews conducted Wednesday night with 350 randomly selected adults nationally also found continued strong support for military action against Iraq after the Jan. 15 U.N. Security Council deadline.

Bush met first yesterday with the top Democratic and Republican leaders of the House and Senate, then with a larger group that included chairmen and ranking minority members of committees concerned with national security. The joint leadership meetings, the first since Bush moved toward offensive action in early November, were followed by briefings for all members by Baker and Defense Secretary Richard B. Cheney.

While there was strong support across party lines for a congressional vote before any military action is ordered, lawmakers appeared uneasy as they anticipated the gravity of the choices they face.

"This is as tough as it gets," said Rep. Richard J. Durbin (D-Ill.), sponsor of a resolution requiring Bush to get congressional approval before going to war. "I've been around here eight years and I've never faced a decision this tough. This is very real and personal. This is neighbors and friends."

In a measure of the cross-currents that were buffeting Congress, Sen. Arlen Specter (R-Pa.) said Harkin and Adams had more support than appeared on the surface, adding that he was sympathetic to their push for an assurance of an early vote.

Rep. Stephen J. Solarz (D-N.Y.), who supports use of force against Iraq, agreed that congressional approval is essential. "If you want Congress in on the landing, you better have Congress in on the takeoff," he said.

"I think we are still pretty well nowhere legislatively. We don't know how to get our hands around it," said House Armed Services Committee Chairman Les Aspin (D-Wis.).

Despite the preoccupation with the Persian Gulf, House Democrats signaled their determination to pass civil rights legislation that was vetoed last year by Bush by assigning it the designation of House Resolution 1. The bill seeks to overturn recent Supreme Court decisions restricting workers' right to sue against alleged job discrimination; Bush contended that it would force employers to impose racial and sex quotas to avoid litigation.

Staff writers David S. Broder and Dan Balz and polling director Richard Morin contributed to this report.