Education Secretary William J. Bennett Tuesday rejected criticisms of his school reform report, saying the education establishment wanted a "whitewash of the problem and . . . a blank check."

Bennett, at a news conference before a White House ceremony marking five years of the administration's school reform initiative, defended his new critique, which concludes that American schools have made only modest gains in recent years.Some educators, including California Superintendent of Public Instruction Bill Honig, have said Bennett's report, "American Education: Making It Work," understates the actual academic accomplishments. Others have said Bennett pointedly ignored the federal government's own responsibility for helping improve schools.

"We have done our part," said Bennett, adding that critics demanding a larger federal role often "mean more cash." He said, "The education establishment," including leaders of the National Education Association, "want a whitewash of the problem and they want a blank check."

He said American schools deserve a grade of C or C-plus. "We could get an A in a couple of years if we really got to it," he said, but later suggested such an accomplishment might take 10 years of work.

Bennett met with reporters before heading to the White House for a ceremony to give President Reagan his report. Teachers, meanwhile, were rallying in Lafayette Park to protest Reagan education policies. The protest was organized by the National Education Association.

Exactly five years ago the National Commission on Excellence in Education delivered a broadside called "A Nation At Risk," which decried "a rising tide of mediocrity" in U.S. schools.

That report made headlines and laid the groundwork for moves in virtually every state to raise graduation standards, boost teacher salaries and, in many instances, impose new accountability on educators.

Bennett's follow-up report, "American Education: Making It Work," was to be released as part of Tuesday's ceremony until it became public over the weekend. Several prominent educators said they agreed with Bennett's conclusion that there have been only modest improvements from reform efforts to date, if not with the entire report.