DETROIT (Reuters) - Public education officials and parents groups in Michigan on Tuesday filed a lawsuit to prevent the governor from funding private schools with public money, arguing a $2.5 million line item in the state budget for school health and safety was a “gateway” to school vouchers.

The Michigan Association of School Administrators (MASA), the Michigan Association of School Boards, ACLU of Michigan, Michigan Parents for Schools and nine other groups filed the lawsuit in the state Court of Claims in Lansing, the state capital, arguing such a move violated state law.

The lawsuit was filed against Michigan Governor Rick Snyder, the Michigan Department of Education and Superintendent Brian Whiston.

The groups asked the court to bar the payments and said they will seek a preliminary injunction later this week to ensure payments are not issued while the matter is pending.

Vouchers are state-funded payments families can use to send their children to private or parochial schools and for expansion of charter schools.

Don Wotruba, executive director of the school boards organization, called the plans “nothing more than a gateway to vouchers.” He added that Michigan voters had already “resoundingly rejected” such a plan, referring to a 2000 ballot proposal that was rejected by 69 percent of voters.

“Our state constitution specifically bans this type of budget action, and we simply cannot allow it,” MASA Executive Director Chris Wigent said in a statement.

Snyder spokesman Ari Adler said in an email the governor’s office does not comment on pending lawsuits.

In July 2016 after the current budget was approved, Snyder asked the state Supreme Court for an opinion on the constitutionality of the spending plan. The court in October declined to give an opinion.

Michigan budgeted $14 billion in the current fiscal year for funding of kindergarten through high school.

Supporters say the budget line item is constitutional as it does not fund educational or curriculum purposes prohibited by the state, but is meant to cover costs associated with state health and safety mandates.

“Health and safety mandates shouldn’t apply to just one segment of the population,” said David Maluchnik, vice president of communications with the Michigan Catholic Conference, the advocacy group for Catholic bishops in the state.

Among the backers of the 2000 Michigan proposal was U.S. Education Secretary Betsy DeVos, the former chair of the Michigan Republican Party who was narrowly confirmed last month. As chair of the American Federation for Children, she has pushed at the state level for vouchers.