The U.S. House of Representatives on Thursday passed a new bill that will fund the Iraq war only through July.

The measure, passed by a 221-205 vote, will give President George W. Bush half the money he has requested for the war effort, with a vote in July on whether to approve the rest, hinging on the Iraqi government's progress in meeting political benchmarks.

The vote sets the stage of a possible second round of showdown between Bush and the Congress on the war funding bill.

Prior to the vote, the House rejected an anti-war bill by a vote of 255-171.

That bill was sponsored by left-wing Democrats who require the U.S. government to start withdrawing combat troops from Iraq within three months.

On May 1, Bush vetoed a war funding bill which requires his administration to start withdrawing troops from Iraq by Oct. 1, with a goal of ending U.S. combat operations there by next March.

However, the Democrats introduced the new bill Tuesday, trying to fund the war in installments so that it could limit Bush's war power.

But without an absolute Democratic majority, it is unclear whether the new bill will clear its way through the Congress before reaching Bush's desk.

House Appropriations Committee Chairman David Obey, who cosponsored the bill, said Democrats have already made several concessions to Bush in the bill, including dropping earlier provisions setting firm dates for leaving Iraq.

In a political shift, Bush said earlier in the day that he is willing to work with lawmakers to include benchmarks for the performance of the Iraqi government in a war spending bill.

However, he also reaffirmed the position that he will veto any bill to pay the war through installments like the one passed by the House.