TRENTON -- Future New Jersey high school students have to prove that they are ready to graduate by passing two standardized tests that fewer than 50 percent of students have conquered thus far.

The state Board of Education on Wednesday approved the PARCC exams as the state's new graduation assessment, and students will now be required pass both the Algebra I and 10th-grade English tests.

The new graduation requirement begins with students entering eighth grade this fall, the Class of 2021.

"That's a goal... that in 2021 students will be ready to demonstrate that they are proficient or above," Education Commissioner David Hespe said. "You have to have an aggressive goal."

The board's vote comes after months of opposition from parents, teachers and local school boards, including protests outside of previous state board meetings. It effectively ends many students' ability to "opt out" of high school exams.

The decision also makes New Jersey an outlier in education. Just 15 states are using high school graduation tests for this year's senior class, and none currently relies solely on an exam from a multi-state testing consortium such as PARCC -- short for The Partnership for Assessment of Readiness for College and Careers.

Save Our Schools NJ, a parent group that opposes PARCC testing, condemned the board's vote.

"Despite unified opposition from parents, school board members, and teachers, the State Board of Education chose to endorse a graduation requirement so inappropriately difficult, it fails nearly 60 percent of all students," the group said in a statement.

In testing last school year, 41 percent of students would have passed the Algebra I exam and 44 percent the 10th-grade English test based on the target scores for the Class of 2021.

Under the new requirement, students who don't pass the exams will have an opportunity to retake them.

Those who still fail can attempt to take advantage of the state's safety net, a portfolio appeal that substitutes a combination of graded class work, school transcripts and other evidence of academic achievement in place of test scores.

However, they must first have participated in all possible high school PARCC exams. The SAT, ACT and other standardized exams will no longer be accepted as an alternative to PARCC tests as they are for students who graduate by 2020.

Earlier this week, Hespe said the low test scores on PARCC Algebra I and 10th-grade English are absolutely a concern. However, the state expects scores to rise as students become more comfortable with the exams, which debuted in 2015.

"Those are areas we know we have to work to do," Hespe said.

New Jersey has asked students to pass a graduation tests since the early 1980s, and state law requires students to prove what they have learned through a basic competency test.

The previous graduation test, which New Jersey abandoned after 2014, was passing too many students who were ultimately enrolled in remedial courses during the first year of college, state officials said.

"Students aren't graduating where they need to be," Hespe said after the vote. "That's not what our obligation is to students. We have to meet that obligation."

One board member, Edithe Fulton, abstained from the vote, saying she didn't feel comfortable supporting the proposal.

Fulton cited the the dwindling number of states participating in the exams and said she does not think students take the tests seriously.

The Education Law Center, which previously sued the state over graduation requirements for the Class of 2016, has already raised legal questions about the new state mandate.

The current state law calls for a basic competency test administered to students in 11th grade. New Jersey will now be using sections of a college and career readiness test that students will take in 10th-grade or earlier.

Adam Clark may be reached at adam_clark@njadvancemedia.com. Follow him on twitter at @realAdamClark. Find NJ.com on Facebook.