The call from Representative John Murtha of Pennsylvania, a leading Democrat voice on military issues, coincides with the release of a new poll on Thursday showing US President George Bush's job approval rating touching a new low of 34%.
"The US cannot accomplish anything further in Iraq militarily. It is time to bring them home," said Murtha, the senior Democrat on the House of Representatives subcommittee that oversees defence spending.
His comments came after a string of sharp attacks by Bush and Vice President Dick Cheney against critics of their Iraq-war policy and handling of prewar intelligence.
Earlier in the week Senate Democratic leader Harry Reid of Nevada accused the White House of "a weak, spineless display of politics at a time of war" with its campaign against war critics.
Reid's comments were echoed by veteran Democratic Senator Edward Kennedy, who said Bush's "pure, unadulterated fear-mongering" had led the country into war.
On Wednesday Cheney hit out at such criticism, describing as "dishonest and reprehensible" accusations that the Bush administration manipulated intelligence to justify the attack on Iraq.
Responding to Cheney's attacks, Murtha, a retired marine colonel and Vietnam veteran, refered to the military draft deferments that kept Cheney out of the call-up to serve during the Vietnam War.
"I like guys who got five deferments and (have) never been there and send people to war, and then don't like to hear suggestions about what needs to be done," Murtha said.
"The US cannot accomplish anything further in Iraq militarily. It is time to bring them home."
Murtha, who supported the Iraq war but has become a critic of the administration's handling of it, urged the president to pull out US troops as soon as it could be done safely. He estimated that would take about six months.
His comments sparked a fresh counter-offensive from Republican members of Congress.
In a statement emailed to Aljazeera.net, Representative Geoff Davis, a Republican from Kentucky, said Democrat critics of the administration's policy "offered no leadership and no solutions" to the situation in Iraq.
"An arbitrary call for the withdrawal of our troops serves only to embolden our enemies and makes meaningless the sacrifice of American men and women," Davis said.
Meanwhile House Speaker Dennis Hastert, an Illinois Republican, said Murtha and other critics "want us to wave the white flag of surrender to the terrorists of the world".
He added: "We must not cower like European nations who are now fighting terrorists on their soil."
The growing political storm comes as the president's approval rating continues to hit new lows.
Calls are growing for Bush to
bring US troops home from Iraq
According to Thursday's poll, published by Harris Interactive, 65% of Americans rate the president's performance as "only fair" or "poor".
Bush's approval rating has been steadily slipping from 50% when he was re-elected in November 2004, to 45% in June to 40% in August of this year, according to the New York-based pollster.
In 2001, at the start of his first four-year term, Bush enjoyed a 56% approval rating.
That shot up to 88% after the September 11 attacks.
In April 2003, during the build-up to the invasion of Iraq, 70% of Americans approved of the president's job performance, but his approval ratings had been steadily falling for a year.
Compared with other two-term presidents at a similar point in their mandates, Bush is now slightly more popular than Richard Nixon's 29% approval rating.
In the latest Harris survey, Vice President Dick Cheney fared even worse than his boss, with just 30% of Americans believing he was doing a good job, down from 35% in August.
Of those polled, 68% said the country was on the "wrong track", while 27% said it was headed in the "right direction".