The Board of Education on Tuesday advanced a proposal to ask for proof of citizenship or legal immigration status from families when they enroll in public school. Hundreds of people gathered outside the building in protest.

The rule would not bar students who are not citizens or legal residents from attending school but is likely to have a chilling effect, opponents said. Parents or guardians would be asked to provide documentation that they and their children are in the country legally, Superintendent of Public Instruction Ryan Walters said Tuesday.

Schools would then submit data, excluding personally identifiable information, to the Department of Education under the proposal. Walters cast the rule as a way to assess state and local educational needs, including English as a Second Language teachers and tutors. But if the Trump administration asked for certain information, Walters said the agency would happily provide it.

The Department of Homeland Security, which oversees Immigration and Customs Enforcement, last week rescinded a policy that prevented enforcement in sensitive areas like schools, hospitals and churches. When asked if he’s concerned about immigration enforcement in schools traumatizing students, Walters said: “I’m concerned about the impact of illegal immigration on education.”

The Migration Policy Institute estimated there are 6,000 undocumented children in Oklahoma schools, or less than 1% of the student population.

Legally, the state can collect citizenship data in connection with government services, said Attorney General Gentner Drummond, according to his spokesperson.

The board approved the rule along with a slate of others by a 4-0 vote, with Walters, Donald Burdick, Katie Quebedeaux and Kendra Wesson voting yes. Two members (Zach Archer and Sarah Lepak) were absent.

The rules move to the Legislature, which can choose to take it up or pass it to the governor’s desk without a vote.