The plan is to add the measure to anti terrorism legislation that is scheduled to be on the Senate floor next week and the week following.
Jim Manley, a spokesman for Reid, declined to discuss the deliberations, saying only, "No final decisions have been made on how to proceed."
Any attempt to limit Bush's powers as commander in chief probably would face strong opposition from Republican allies of the administration in the Senate and could also face a veto threat.
The decision to try to limit the military mission marks the next move in what Reid and other Senate war critics have said will be a multistep effort to force a change in Bush's strategy and eventually bring an end to US participation in the nearly four-year-old war.
Earlier efforts to pass a nonbinding measure critical of Bush's decision to deploy 21,500 additional troops ended in gridlock after Senate Republicans blocked votes on two separate measures.
The emerging Senate plan differs markedly from an approach favored by critics of the war in the House, where a nonbinding measure passed last week.
Speaker Nancy Pelosi has said she expects the next challenge to Bush's war policies to come in the form of legislation requiring the Pentagon to adhere to strict training and readiness standards in the case of troops ticketed for the war zone.
The leading advocate of that approach, Representative John P. Murtha, Democrat of Pennsylvania, has said it would effectively deny Bush the ability to proceed with the troop buildup that has been partially implemented since he announced it in January.
Some Senate Democrats have been privately critical of that approach, saying it would have virtually no chance of passing and could easily backfire politically in the face of Republican arguments that it would deny reinforcements to troops already in the war zone.
