The White House is likely to face its most significant confrontation with Congress so far over its handling of the Iraq war after House Democrats agreed on Thursday on plans to debate a simple resolution next week that would oppose the escalation of the war but express support for funding the troops already on the ground.

Agreement on the non-binding resolution could attract the support of disaffected Republicans and enable a symbolic bipartisan expression of no confidence in the Iraq policy. The shift of focus to the House comes after the Senate Republican leadership this week stymied debate on a non-binding Iraq war resolution by exploiting procedural motions.