U.S. President George W. Bush walks with Deputy Chief of Staff Karl Rove towards the Oval Office of the White House in Washington, March 23, 2007. [Reuters]

WASHINGTON - With his go-it-alone approach on Iraq, US President Bush is flouting Congress and the public, so angering lawmakers that some consider impeachment an option over his war policy, a senator from Bush's own party said Sunday.

Meanwhile, the Senate's No. 2 Republican leader harshly criticized House Democrats for setting an "artificial date" for withdrawing troops from Iraq and said he believes Republicans have enough votes to prevent passage of a similar bill in the Senate.

"We need to put that kind of decision in the hands of our commanders who are there on the ground with the men and women," said Sen. Trent Lott, R-Miss. "For Congress to impose an artificial date of any kind is totally irresponsible."

GOP Sen. Chuck Hagel of Nebraska, a member of the Senate Foreign Relations Committee and a frequent critic of the war, stopped short of calling for Bush's impeachment. But he made clear that some lawmakers viewed that as an option should Bush choose to push ahead despite public sentiment against the war.

"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," said Hagel, who is considering a 2008 presidential run.

The Senate planned to begin debate Monday on a war spending bill that would set a nonbinding goal of March 31, 2008, for the removal of combat troops.

That comes after the House narrowly passed a bill Friday that would pay for wars in Iraq and Afghanistan this year but would require that combat troops come home from Iraq before September 2008 -- or earlier if the Iraqi government did not meet certain requirements.

On Sunday, Hagel said he was bothered by Bush's apparent disregard of congressional sentiment on Iraq, such as his decision to send additional troops. He said lawmakers now stood ready to stand up to the president when necessary.

In the April edition of Esquire magazine, Hagel described Bush as someone who doesn't believe he's accountable to anyone. "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," Hagel told the magazine.

In his weekly address Saturday, Bush accused Democrats of partisanship in the House vote and said it would cut the number of troops below a level that U.S. military commanders say they need. Vice President Dick Cheney also accused Democrats of undermining U.S. troops in Iraq and of sending a message to terrorists that America will retreat in the face danger.

"We have clearly a situation where the president has lost the confidence of the American people in his war effort," Hagel said. "It is now time, going into the fifth year of that effort, for the Congress to step forward and be part of setting some boundaries and some conditions as to our involvement."

"This is not a monarchy," he added, referring to the possibility that some lawmakers may seek impeachment. "There are ways to deal with it. And I would hope the president understands that."

Lott said setting withdrawal dates is a futile and potentially dangerous exercise because Bush has made clear he will veto any such legislation.

"There are members in the Senate in both parties that are not comfortable with how things have gone in Iraq," Lott said. "But they understand that artificial timetables, even as goals, are a problem. ...We will try to take out the arbitrary dates."

Sen. Bill Nelson, D-Fla., said the Senate bill seeks to heed the recommendations of the bipartisan Iraq Study Group by setting a goal of withdrawing some troops while leaving others behind to train the Iraqi army for border patrol and other missions.

"That, combined with a very aggressive, diplomatic effort in the region is what we're going to need to have," he said.

Sen. Dianne Feinstein, D-Calif., said she believed that setting a timetable was appropriate but declined to predict whether it would garner enough Senate votes to pass.

"People of this country have spoken overwhelmingly. It's been constant now," Feinstein said. "They want us out. It is time for the Senate to weigh in. I hope we will have the votes."

Hagel spoke on ABC's "This Week," Feinstein and Lott appeared on "Fox News Sunday," and Nelson was on CNN's "Late Edition."