WASHINGTON — President Bush's Iraq war funding request collapsed in the House Thursday as anti-war Democrats and Republicans unhappy about added domestic funding combined to kill — for now — $163 billion to support U.S. troops overseas.

The unlikely coalition formed when Republicans expected to provide the winning margin for the Iraq and Afghanistan funding instead sat out the vote in protest.

The GOP revolt was a response to Democratic strong-arm tactics in advancing the must-pass measure, as well as their efforts to add money for the unemployed and an expansion of GI education benefits.

The defeat of the Iraq funding measure came on a 149-141 tally. Nearly two-thirds of the House's Democrats voted against continuing to fund the war as 132 Republicans sat out the vote in protest.

Democrats then forced through a nonbinding plan seeking an exit from Iraq by December of next year. The 227-196 vote on the measure broke mostly along party lines.

Thirty-two Republicans joined Democrats on a 256-166 vote to sharply boost education benefits for Iraq-Afghanistan veterans under the GI Bill— despite an accompanying tax surcharge on the wealthy and small businesses — and voted to provide a 13-week extension of unemployment benefits.

Republicans said the strategy by Democrats to load the war funding measure with non-war provisions like extending unemployment benefits unnecessarily delays getting funding to troops in the field.

House action on the bill was the first act in a complicated legislative dance that promises to spill over into June, when the Pentagon will have to send out warnings of possible furloughs to civilian employees and contract workers.

The add-ons for the unemployed and the new college benefits under the GI Bill represented the price demanded by Democrats for approving Bush's long-stalled request for additional war funding.

The new GI Bill essentially would guarantee a full scholarship at any in-state public university, along with a monthly housing stipend, for people who serve in the military for at least three years. It is aimed at replicating the benefits awarded veterans of World War II and would cost $52 billion over 10 years.

To pay for it and adhere to budget rules requiring new benefit programs not add to the deficit, the Democratic plan would impose a surtax on individuals with incomes above $500,000. Couples would pay the tax on income exceeding $1 million.