Since the introduction of the Murtha resolution, many members of Congress, particularly in the Democratic Party, have rallied around the strategy of a phased troop withdrawal. In the 2007 Congressional session, critics of the war have sought to tie additional war appropriations to a specific timetable for withdrawal. On March 23, 2007, the House of Representatives passed an Iraq spending bill that requires that troops begin withdrawing in March 2008 and that most US forces be out of Iraq by August 31, 2008.