The longest-serving school superintendent in the Washington area, Loudoun County's Edgar B. Hatrick III, this week joined a growing number of Virginia educators in denouncing a federal requirement to give tougher reading tests to immigrant students. But whether Loudoun will, like Fairfax County, defy the mandate remains an open question.

Hatrick said in an interview that it was "wrong-headed" to give grade-level tests to students in the early stages of learning English. Until now, Virginia schools have given such students proficiency tests that do not cover the same material as the exams that native English speakers must take.

"It's a frustration to me because it's so obvious. I don't understand why policymakers don't understand," Hatrick said Wednesday. "I think it's ethically and professionally wrong to give a child a test for which they can't be prepared and aren't prepared."

Denunciations of the No Child Left Behind law's testing rules are multiplying in immigrant-rich Northern Virginia. In Fairfax and Arlington County, educators are preparing to defy the rules even though they are at risk of losing federal aid; other area officials are moving more cautiously.

Federal officials have said repeatedly that grade-level testing is needed for immigrant students after they have been in U.S. schools for one year, a requirement they say will help hold schools to high standards. Most states, including Maryland, are following the rules. So are D.C. public schools, officials say.

U.S. Education Secretary Margaret Spellings has criticized Virginia educators who are resisting. "It's time to remember that yes, Virginia, there is a Standards Clause," Spellings wrote recently in a caustic open letter.

Fairfax, with the region's largest school system, has led the state's rebellion. The county School Board voted in January to continue giving proficiency tests to immigrant students who have not progressed enough to take grade-level tests that assume language fluency. Fairfax school officials appear to be standing firm even though the U.S. Department of Education has threatened to withhold $17 million in aid if the county follows through with its plan.

The Arlington School Board has also authorized officials to shield some immigrant students from tests the federal government insists they take. "Most people believe the rule makes no sense," said Arlington School Superintendent Robert G. Smith.

The Alexandria School Board has not taken similar action. "Right now, there are not plans to do anything different from what's required," Alexandria schools spokeswoman Amy Carlini said yesterday. She added that some School Board members want to determine how much federal funding is at stake.

The Prince William County School Board is tiptoeing around the battle. It has passed a resolution that expresses "concern" over the federal requirements but notes that the school system will abide by them. School Board Chairman Lucy S. Beauchamp (At Large) said that she applauds Fairfax's stand but that Prince William cannot risk losing federal aid because it is already facing a significant budget shortfall.

In Loudoun, Hatrick and his staff have proposed a resolution similar to what Fairfax and Arlington have adopted. Officials estimate that as much as $2 million in federal aid could be at risk if the county defies the federal government.

Loudoun School Board Vice Chairman Tom Reed (At Large) said he supported the staff recommendation. "I think the decision about who should take which tests should be at the classroom level, not imposed from Washington," he said.

The Loudoun board has not yet scheduled a vote. Loudoun board member J. Warren Geurin (Sterling) said the county should follow the federal requirement.

"We don't have to take a sharp stick and poke the federal government in the eye," Geurin said.

Staff writers Tara Bahrampour and Ian Shapira contributed to this report.