WATERLOO (AP) — An Amish father who says childhood vaccines run counter to his family’s religious beliefs is suing to overturn New York’s ban on religious exemptions that let unvaccinated children attend school.

Jonas Stoltzfus’ lawsuit contends the law violates constitutionally protected religious rights. He says he has been told that his three children will no longer be able to attend Cranberry Marsh School in Seneca County unless they are immunized.

The state in June did away with religious exemptions for vaccines amid the worst measles outbreak in 27 years. That left more than 26,000 students who had the exemptions to either receive their shots or be homeschooled.

Stoltzfus’s attorney says most students and teachers at the small, private school are unvaccinated and that the school and others like it could be forced to close.