U.S. states and school districts in Maine have reached a tentative agreement to expand charter schools to more than 1 million kids by 2025, according to the state Education Department.

Under the tentative agreement, which would not take effect until the next fiscal year, state officials will start piloting the expansion of the existing, privately run schools by next year.

The move comes amid a statewide backlash against charter schools that has included a ballot initiative to ban them in 2016.

The charter movement has been criticized by education advocates and by some local officials.

The Maine Education Association (MEA) has called the deal a win for parents and children, who will have more choice and a greater chance to reach their potential.

The school system will get to the milestone in about two years, according the MEA.