Democrats are this week expected to approve $100 billion to pay for continuing the Iraq war while setting timetables for withdrawing troops.
But President Bush has promised to veto any bill setting dates for removing US combat soldiers from the Iraq war, now in its fifth year.
When a Democratic-controlled panel of Senate and House of Representatives members meets today to iron out differences between their respective bills, the product is expected to contain 2008 withdrawal dates.
Last month, the House approved a bill setting a September 1st, 2008, deadline for all US combat troops to leave Iraq. The Senate's softer approach calls for some troop withdrawals this year leading to a nonbinding goal of having most of the 146,000 soldiers leave Iraq by March 31st, 2008.
The full House could vote on Wednesday on the controversial war-funding bill, the same day Gen David Petraeus, commander of US forces in Iraq, is due to brief senators.
Democrats say they are uncertain what will happen after Mr Bush vetoes their war money bill. They know they will have to produce another bill to fund the troops in Iraq but are divided over what conditions they can attach and still win Mr Bush's signature.