The union for Maryland teachers joined other education groups yesterday in a last-ditch effort to halt or slow the state's plan to make passing standardized tests a requirement for graduation.

The State Board of Education approved the plan in February and is scheduled to take a vote on its final details next month. Under the proposal, the Class of 2009 -- today's seventh-graders -- would have to pass the Maryland High School Assessments in English, algebra, government and biology to receive a high school diploma.

At a public hearing yesterday in Baltimore, state teachers union President Patricia A. Foerster urged the board to do away with that idea. Representatives of several groups that advocate for special education students also reiterated concerns that high-stakes testing puts those with disabilities at a disadvantage.

"There is so much more to learning that cannot be assessed by a paper-and-pencil test," Foerster said.

Other critics of the plan, including the Montgomery County school board and the Maryland Association of Boards of Education, asked the state school board to delay its final vote to allow more time to study the issue.

But State Superintendent of Schools Nancy S. Grasmick said that Maryland has waited too long to introduce high school "exit exams," and that she is committed to the 2009 deadline. High school students in 20 states, including Virginia, take standardized tests as a graduation requirement.

There is "no slippage on my part at all, although sometimes I feel I am fighting an uphill battle," Grasmick said yesterday.

Critics worry that schools might place too much importance on the tests and that students who think they cannot pass the exams might drop out. For the past two years, high school students have been required to take the Maryland High School Assessments, but the results have had no effect on their graduation status.

Preliminary results of a study on exit exams in six states, to be released next month, show that "there's nothing in those tests that it would be unreasonable for a high school graduate to know," said Michael Cohen, president of Achieve Inc., a nonprofit group that helps states improve and coordinate their testing efforts. Cohen outlined the findings of Achieve's study at the Maryland school board meeting yesterday.

Under the state's plan, students can fail one or more of the tests as long as they earn a passing score when the four results are added together. Students can take the tests several times.

The maximum score on each exam is 800, and students must receive a combined score of 1613 on all four to get a diploma. However, there is a catch: Students will not receive a diploma if they score lower than a minimum target -- yet to be set by the board -- on any of the tests.

That plan has won the support of the state's 24 public school superintendents, as well as the Maryland Association of Student Councils.

But Elliott Wolf, a senior at Montgomery Blair High School in Silver Spring, told board members yesterday that the exams could have a devastating effect at his school, where about 10 percent of the students last year spoke limited English. None of them passed the English portion of the 2003 state assessments, according to state records.

"These tests are . . . badly implemented, and the students are suffering as a result," Wolf said.