WASHINGTON — Senator Hagel, a Republican of Nebraska who is predicting that President Bush will face calls for impeachment if he ignores Congress on the war, will introduce binding legislation this week to begin the withdrawal of soldiers from Iraq.

Speaking on ABC’s “This Week,” Mr. Hagel said he would introduce a binding resolution this week “focused on redeployment, training and equipment.” Mr. Hagel’s co-sponsor for the new Iraq resolution is Senator Webb, a Democrat of Virginia who has introduced legislation in the Senate to prevent the president from taking any military action against Iran and who won his election to his first term in the Senate last November by running on an anti-war platform. Mr. Webb, who served in the Reagan administration as the secretary of the Navy, has emerged as a favorite of the Democratic online group, MoveOn.org.

Mr. Hagel’s pending resolution on Iraq puts him at odds with his party, which has won back many of the Republicans who in December began raising doubts about the war. On Friday, the House Democrats received only two Republican votes for a supplemental budget bill that would mandate a withdrawal of forces from Iraq by 2008. Eight days before, Senator Gordon Smith of Oregon was the only Republican who voted for the binding resolution sponsored by Senator Reid, the majority leader, mandating a timetable for withdrawal. Mr. Hagel voted with his party against that resolution.

However, Mr. Hagel yesterday indicated his days of voicing skepticism about the war but voting with the president had ended. “I will not accept the status quo, I will not continue to support with my vote the current policy,” he said.

He went further in an interview with the April issue of Esquire magazine. “He’s not accountable anymore, which isn’t totally true. You can impeach him, and before this is over, you might see calls for his impeachment. I don’t know. It depends on how this goes,” he said in that interview.

When asked yesterday on ABC what he meant by his comments to the magazine about impeachment, the senator said, “Any president who says, ‘I don’t care,’ or ‘I will not respond to what the people of this country are saying about Iraq or anything else,’ or ‘I don’t care what the Congress does, I am going to proceed’ — if a president really believes that, then there are —what I was pointing out, there are ways to deal with that.”

Yesterday a senior Senate staffer close to the Senate Republican leader said he did not expect Mr. Hagel would vote for a timetable for withdrawal, despite his comments.

“He was with us last time,” this source wrote in an e-mail. “He doesn’t like arbitrary withdrawals, and he doesn’t want to prevent the funding bill from getting through. The Reid language is a poison pill.”

A former communications director for the Republican National Committee, Clifford May, yesterday said he was disappointed in Mr. Hagel. “That’s really disappointing and really rather sad to hear a U.S. senator threaten the president with impeachment for attempting to do his job as commander in chief,” said Mr. May, now president of the Foundation for the Defense of Democracies. “Senator Hagel voted to confirm General Petraeus as the commander in Iraq. He should not have done so if he was planning to undermine General Petraeus’ mission.”

Mr. Hagel yesterday said he was particularly angry about the president’s reaction to the House passage of the Iraq supplemental budget, which the president said in his radio address this weekend he would veto if it crossed his desk. That bill gives the White House $24 billion more than it asked for to fund the troop surge in Baghdad and Anbar, but it also mandates a timeline and a cut off of war funding after August 31, 2008.

The president on Saturday in his national radio address warned that if Congress does not appropriate the funds for the military by April 15 in a clean bill, then the military’s mission in Afghanistan and Iraq could face disruptions.

“By choosing to make a political statement and passing a bill they know will never become law, the Democrats in Congress have only delayed the delivery of the vital funds and resources our troops need,” Mr. Bush said. “The clock is running.”