The Bush administration yesterday proposed nearly $500 million in federal funding to help displaced private school students from the Gulf Coast enroll in private schools elsewhere in the aftermath of Hurricane Katrina.

The proposal, fleshing out a goal President Bush had announced in a speech to the nation Thursday night, would amount to the largest federal school voucher program ever, if enacted. A groundbreaking school voucher program in the District receives about $14 million a year in federal funding.

The new administration proposal drew immediate criticism from senior congressional Democrats and teacher union leaders who have long opposed vouchers as a drain on scarce public school resources. But private school voucher advocates hailed it as a measure needed to address an immediate educational crisis.

Separately, the Republican chairman and ranking Democrat on the Senate Health, Education, Labor and Pensions Committee this week introduced a bipartisan education relief bill. The proposal from Sens. Mike Enzi (Wyo.) and Edward M. Kennedy (Mass.) omitted school vouchers.

Education Secretary Margaret Spellings outlined the administration proposal in a two-page summary posted on her department's Web site. The summary stated that the administration would propose as much as $488 million to compensate Katrina evacuees "for costs associated with attending . . . private schools." The funding would be capped at $7,500 per child.

The funding would be included in a $2.6 billion education relief plan meant to aid 372,000 students who had attended public and private schools in areas swamped by the hurricane on Aug. 29 and by the ensuing floods. More than 600 displaced students have enrolled already in the Washington area, including more than 90 in Catholic schools.

To support its private school proposal, the administration cited data showing that "an above average number" of children in southeastern Louisiana had attended private schools in battered New Orleans and surrounding suburbs -- 61,000 students out of a total of 187,000 enrolled in public and private schools in four parishes.

That ratio of students attending private schools -- nearly a third -- was far higher than the national average of 11 percent, the administration stated.

"This an unprecedented situation, and we have large numbers of kids who are displaced, public school students and private school students," Spellings told reporters in a conference call.

Sen. Lamar Alexander (R-Tenn.), a former education secretary and member of the health education committee, endorsed the administration's private school relief plan. "Katrina didn't discriminate among children, and we shouldn't either," Alexander said in a telephone interview. "I don't see this as the beginning of a big new voucher program for K through 12, even though I'd be for that."

A spokesman for committee Republicans, Craig Orfield, said Enzi had not yet reviewed the administration proposal.

In a statement on his Web site, Kennedy said he applauded Bush's overall education relief plan. "But I am extremely disappointed that he has proposed providing this relief using such a politically charged approach," Kennedy said. "This is not the time for a partisan political debate on vouchers."

The bulk of the funding in the administration plan is a $1.9 billion proposal for aid to public school systems affected by displaced students. The money would go to Louisiana and Mississippi and to school systems elsewhere, including charter schools, that enroll at least 10 displaced students. Another $227 million would help students, colleges and universities affected by the hurricane. For example, students in hard-hit Gulf Coast areas would be forgiven six months of interest on student loans. Colleges and universities would be eligible for $1,000 for each displaced student they enroll.

Staff writer V. Dion Haynes contributed to this report.

Jaylen Moore, 10, sits in his new classroom at Ogden Elementary School in Chicago after he and his family fled Gulfport, Miss., and Hurricane Katrina. President Bush proposed $488 million for displaced private school students.