Washington ? CIA Director George Tenet told lawmakers Tuesday that Iraqi President Saddam Hussein, if provoked by fears of an imminent U.S.-led attack, might assist Islamic extremists in launching an attack against the United States with weapons of mass destruction.

Saddam might see it as “his last chance to exact vengeance by taking a large number of victims with him,” Tenet wrote in a letter.

Tenet’s assessment came as both the House and Senate debated a resolution to authorize President Bush to use force against Iraq and followed Bush’s assertion that the Iraqi leader might be planning a chemical or biological attack on U.S. interests.

It is unlikely that such an attack by Saddam would come unless he felt cornered, Tenet’s letter suggested.

Still, Tenet wrote, “Iraq’s increasing support to extremist Palestinians, coupled with growing indications of a relationship with al-Qaida, suggest that Baghdad’s links to terrorists will increase, even absent U.S. military action.”

In a statement issued later, Tenet said there was “no inconsistency” between his letter and Bush’s policy.

“Although we think the chances of Saddam initiating a weapons of mass destruction attack at this moment are low in part because it would constitute an admission that he possesses weapons of mass destruction there is no question that the likelihood of Saddam using weapons of mass destruction against the United States or our allies in the region for blackmail, deterrence, or otherwise, grows as his arsenal continues to build,” the statement said.

Bush’s drive to win war authority, meanwhile, hit a snag in the Senate.

Sen. Robert Byrd, D-W.Va., a fierce opponent of the president’s Iraq war resolution, was using parliamentary tactics to delay the measure. Senate Majority Leader Tom Daschle, D-S.D., said that could easily put off a final vote until next week.

However, eventual approval of the administration-backed resolution appeared likely, and it was gaining broad bipartisan support in both chambers.

Both the House and the Senate worked into the evening on the measure and a final House vote was expected by late Thursday.

Secretary of State Colin Powell made appearances on both sides of Capitol Hill to urge lawmakers to pass the resolution with large bipartisan margins and without amendments.

“I think the resolution is timely, and we need it now,” Powell told reporters. He said it would help strengthen his hand at the U.N. Security Council.

Bush warned Monday that Saddam might attempt “cruel and desperate measures,” including using chemical and biological weapons against U.S. forces or his own people.

But Tenet, in the letter read before a joint hearing of the House and Senate intelligence committees, suggested Baghdad “for now appears to be drawing a line short of conducting terrorist attacks with conventional or chemical or biological weapons.”

Should Saddam conclude that a U.S.-led attack against his country could not be deterred, “he probably would become much less constrained in adopting terrorist action,” said Tenet.

Tenet also briefed Senate members privately. And, Tuesday night, the Senate Intelligence Committee released the full text of Tenet’s letter.

The Bush administration contends that going after Saddam is necessary because he has the capability to use weapons of mass destruction and is trying to expand it. The administration also stresses that he has used them in the past.

Tenet provided a slightly different take, suggesting that just because Saddam has such weapons doesn’t necessarily mean he’ll use them now.