WASHINGTON, May 8: Democrats sought to exploit signs of cracks in Republican unity over Iraq on Tuesday, as President George W. Bush's backers accused their foes of seeking to ration funding for battle-scarred troops.

The latest vitriol rattling Washington came as Democratic leaders in Congress mulled their next move in the titanic struggle over war powers with the White House, following Bush's veto of their withdrawal timetable last week. Signs of an expiry date on Republican patience over Bush's strategy to surge nearly 30,000 more troops into the war appeared to offer an opening to Democrats determined to force the withdrawal of most combat troops.

John Boehner, the Republican leader in the House of Representatives, caused a stir on Sunday when he said his congressional colleagues needed to see progress in the surge by mid-to-late this year. “By the time we get to September, October, members are going to want to know how well this is working, and if it isn't, what's Plan B?” Boehner said on Fox News Sunday.

September is emerging as a key date for Iraq strategy, as it is then that General David Petraeus, commander of the 146,000 US troops in the country, is expected to assess the surge's progress. Democrats immediately seized on the remarks to claim cracks were opening in so far staunch Republican support for the administration, which has argued that contemplating a “Plan B” would consign the surge to failure.

“The House Minority Leader now seems to be saying that he and his colleagues agree that there must be time limits on the president's current course in Iraq,” Senate Democratic Majority leader Harry Reid said on Monday.

“What is also revealing, and somewhat disturbing, is that the Republican leader is willing to allow our troops to stay in Iraq with a failing strategy until he and his colleagues decide it is time to part with the president.” Democratic leaders have said that they believe Republicans will become more anxious about the unpopular war as 2008 congressional polls approach, and therefore will be more likely to break with Bush.

House Democrats were meeting in closed session on Tuesday, as leaders tried to produce a funding bill that Bush would sign that was also palatable to their restive party, much of which is fiercely anti-war.

Democrats have so far refused to confirm expectations that they will send a new funding bill, to replace the $124bn version Bush vetoed, stripped of timelines for the withdrawal of troops.—AFP