Congressional backers of President Bush's Persian Gulf policy Thursday unveiled a resolution that would authorize him to take the United States to war against Iraq, and they predicted it would pass by this weekend.

As lawmakers convened to debate the question of war and peace, Bush's supporters in both parties put forward a resolution clearing the president "to use United States armed forces" to back up United Nations goals of forcing Iraq from Kuwait and restoring its legitimate government.At the same time, Senate Democrats introduced their own resolution asserting that continued use of international sanctions and diplomacy "is the wisest course at this time and should be sustained."

The opposing resolution does not rule out the eventual use of force if all other efforts are exhausted. But it states that the Constitution gives "all power to declare war" to Congress and that lawmakers will give quick consideration to any future presidential request for war authority.

Majority Leader George Mitchell, on the Senate floor, said Bush is seeking "a blank check" from Congress that the Maine Democrat declined to support. "We cannot and should not rule (the use of force) out," to chase Iraq from Kuwait, he said. "The issue is how best to achieve that goal."

Bush's supporters, led by Rep. Stephen Solarz, D-N.Y., and House Republican Leader Robert Michel of Illinois, said their chances for winning approval were bolstered by the dismal outcome of Wednesday's meeting in Geneva between Secretary of State James A. Baker III and Iraqi Foreign Minister Tariq Aziz.

"After Secretary Baker received a cold shower from Foreign Minister Aziz yesterday, support . . . is likely to increase," Solarz said at a news conference.

The group said it believed freeing Bush to use force was, in Solarz's words, "the last, best hope for a peaceful resolution" of the crisis.

An affirmative vote will leave no room for doubt that the United States is serious in its threat to inflict severe damage on Iraq for its Aug. 2 invasion of its small neighbor, they said.

A competing resolution, supported by Democratic leaders in the House and Senate, calls for giving the international economic embargo against Iraq and diplomacy more time to work before a decision is made to use force.

Rep. Lee Hamilton, chairman of the House Foreign Affairs Committee's Middle East subcommittee, said Thursday that Iraq's actions in talks in Geneva on Wednesday have helped Bush's position in Congress.