WASHINGTON — House Democratic leaders planned to brief party members yesterday on new legislation that would fund the Iraq war through July, then give Congress the option of cutting off money after that if conditions do not improve.

If members agree to back the plan as expected, a vote on the new war spending bill could come as early as this week. The proposal, pitched last week by Rep. David Obey, a Democrat of Wisconsin, was first disclosed Thursday by the Associated Press.

White House spokesman Tony Snow yesterday called the approach “just bad management.”

“We think it is appropriate to be able to give commanders what they are going to need, and also forces in the field, so that you can make long-term decisions in trying to build the mission,” Mr. Snow said.

Congressional Republicans immediately dismissed the Democratic proposal as unfairly rationing funds needed in combat and said their members would not support it. Democrats “should not treat our men and women in uniform like they are children who are getting a monthly allowance,” said Rep. John Boehner, a Republican of Ohio, his party’s leader.

Added Rep. Adam Putnam, a Republican of Florida, after a GOP caucus meeting yesterday: “It’s a irresponsible approach. You do not fund wars 60 days at a time.”

The Democratic proposal responds to President Bush’s veto last week of a $124.2 billion bill that would have funded the war in Iraq, among other things, but demanded troops begin coming home on October 1. Republicans agreed to uphold the veto, and Democrats were forced back to the drawing board.

House Democrats want to provide a bill that supports the troops, but not give Mr. Bush a blank check on the deeply unpopular and costly war. Further complicating matters, several House liberals oppose funding the war at all while other more conservative Democrats are reluctant to tie strings to a bill needed by the troops.

The new version is likely to meet resistance in the Senate. Several Senate Democrats said they would oppose a short-term funding bill because it leaves open the question of whether troops will get the resources they need after July.

“There’s the question of why it wasn’t fully funded,” said Senator Nelson, a Democrat of Nebraska.

If the House version of the bill fails in conference with the Senate, Democratic leaders say their members will have other chances to affect Iraq policy. Party leaders have pointed to the 2008 defense authorization bill, which helps to set Pentagon policy, as well as the 2008 appropriations bills.

However, that plan could meet resistance by members reluctant to watch their carefully crafted bills sink under a presidential veto. Rep. Ike Skelton, a Democrat of Missouri and the chairman of the Armed Services Committee, has drafted a defense authorization bill that requires U.S. officials to report on progress made on the war. But according to a panel aide familiar with the draft, the bill so far does not include a tough mandate to end the war.