The top American military and political figures in Iraq will today seek to persuade Congress that the current military strategy is working, at the start of two days of hearings and a report that could determine the future of the US presence in Iraq.
Democrats have long viewed today's progress report by Gen David Petraeus and US ambassador Ryan Crocker as a potential turning point in the political debate over Iraq. President George Bush, who will deliver his own report to Congress and make an address to the nation later this week, hopes that today's testimony will buy more time for his strategy of increasing US troop numbers in Iraq.
Gen Petraeus is expected to tell congressmen that the 30,000 extra troops have helped to improve security dramatically, notably in Anbar province, where former Sunni insurgents have recently joined US forces in confronting Islamist radicals.
The general will also point to a fall in the level of sectarian killings in Baghdad, but he is expected to acknowledge that improvements in security have not been matched by political progress.
Democrats made clear yesterday that today's testimony will not deflect them from seeking an early withdrawal of US troops, with Senate foreign relations committee chairman Joe Biden dismissing Mr Bush's strategy in Iraq as "dead flat wrong".
"The reality is that although there's been some mild security progress, there is in fact no security in Baghdad or Anbar province where I was dealing with the most serious problem, sectarian violence," he said.
Mr Bush announced the military surge in January, after he rejected the bipartisan Iraq Study Group's recommendation that most US combat troops should withdraw from Iraq by April 2008.
The president said that more troops were needed to create adequate security, particularly in Baghdad, to allow the Iraqi government of Nuri al-Maliki to introduce political reforms aimed at reconciliation between Iraq's Shia, Sunni and Kurdish communities.
Three reports on the war last week - from US intelligence agencies, the non-partisan Government Accountability Office and a commission headed by former Gen James L Jones - said that, although there had been some military successes, there was little political progress.
In a letter to US troops last Friday, Gen Petraeus acknowledged that he had hoped for tangible political progress in Iraq by now. "One of the justifications for the surge, after all, was that it would help create the space for Iraqi leaders to tackle the tough questions and agree on key pieces of 'national reconciliation' legislation. It has not worked out as we had hoped," he wrote.
Mr Maliki insisted yesterday that his government had made progress "in all directions" and urged neighbouring countries and western powers to help him to stop "evil" from destabilising the region.
"This government is working hard to develop the political situation. It has made many gains despite the huge destruction left by the former regime. We are at the beginning of the road, but at the same time, we say that what has been achieved is something promising," he said.
Democrats have made clear that they will press Gen Petraeus and Mr Crocker on whether the troop surge has succeeded in reshaping the political landscape in Iraq, or has simply made tactical gains that leave the underlying conflict unchanged.
A Washington Post/ABC News poll published yesterday showed that 60 per cent of Americans do not believe that US forces are making significant progress towards restoring order in Iraq and other polls show that two out of three Americans want to start withdrawing troops.