WASHINGTON -- Leaders of both parties said yesterday that the House is prepared to cut off money to finance the Air Force's $62.7 billion F-22 fighter program, a highly unusual decision that has stunned the Pentagon and military contractors.

The stage for a full House vote next week was set yesterday when the House Appropriations Committee unanimously approved a $268 billion Pentagon spending bill denying the Air Force the $1.8 billion it sought to finance six more F-22s.

The cutoff is supported by Speaker Dennis Hastert, an Illinois Republican, Minority Leader Richard A. Gephardt, a Missouri Democrat, and key Republican leaders who say the fledgling fighter is simply too expensive to build at about $200 million a plane.

The Pentagon reacted fiercely. "This decision, if enacted, would for all practical purposes kill the F-22 program, the cornerstone of our nation's global air power in the 21st century," Defense Secretary William S. Cohen said yesterday in a letter to Congress.

Nothing quite like this has happened in decades, according to senior members of Congress and veterans of Pentagon spending wars. Congress almost never kills major weapons systems that are about to reach the assembly line. And the F-22 is the biggest Air Force weapons program of all.