Democrats are challenging the US president's power to wage war, contending they have found a way to block a troop increase in Iraq and prevent any pre-emptive invasion of Iran.
Congress will vote on a non-binding measure stating opposition to George Bush's decision to send 21,500 more troops to Iraq.
The House of Representatives is expected to pass the measure on Friday, and the senate plans to hold a test vote on Saturday.
Democrats say the votes are the first step towards forcing Bush to change course in a war that has killed more than 3,100 US soldiers and lost favour with voters.
John Murtha, a Democratic representative who chairs the house panel that oversees military spending, said: "This country needs a dramatic change of course in Iraq and it is the responsibility of this congress to consummate that change."
Murtha is preparing legislation that would set strict conditions on US troop combat deployments, including a year's rest between combat tours. Ultimately, the congressman says his measure would make it impossible for Bush to maintain his planned deployment of a total of about 160,000 troops for months on end.
Murtha's proposal might also block the funding of
military operations inside Iran - a measure intended to send a signal to Bush that he will need congress' blessing if he is planning another war.
In an interview broadcast on the website movecongress.org, Murtha told an anti-war group that "the president could veto it, but then he wouldn't have any money".
Nancy Pelosi, the Democratic leader of the house, said on Thursday that Bush consistently said he supports a diplomatic resolution to differences with Iran "and I take him at his word".
At the same time, she said: "I do believe that congress should assert itself, though, and make it very clear that there is no previous authority for the president, any president, to go into Iran."
Bush said at a news conference on Wednesday that there is no doubt the Iranian government is providing armour-piercing weapons to kill American troops in Iraq.
But he backed away from claims by senior US military officials in Baghdad that high-ranking Iranian officials were responsible.
Critics of the Bush administration have accused the president of looking for a pretence to attack Iran.
In a speech on Thursday, Bush said he expects congress to live up to its promise to "support the troops".
He said: "We have a responsibility, Republicans and Democrats have a responsibility, to give our troops the resources they need to do their job and the flexibility they need to prevail."
In the third day of the lower house debate on the war, Republican combat veterans spoke out against the Democratic resolution.
Sam Johnson, a Republican representative who was a prisoner of war during Vietnam, said: "The enemy wants our men and women in uniform to think their congress doesn't care about them.
"We must learn from our mistakes. We cannot leave a job undone like we left in Korea, like we left in Vietnam, like we left in Somalia."
Duncan Hunter, the senior California Republican representative on the House Armed Services Committee, called the political manoeuvring by Democrats to micromanage the war "extremely dangerous".
He said: "It could stop reinforcements from arriving in time to stop major casualties in any of a number of scenarios."
Democrats face opposition in the senate as well.
Lindsey Graham, a Republican senator, said: "I will do everything in my power to ensure the house resolution dies an inglorious death in the senate."
Source: Jazeera
Our button
print version
