An NEA spokesperson said in an email that the union was bargaining in good faith with staffers, and accused those who went on strike of “abandoning” members by disrupting the Philadelphia assembly. The NEA argues that the staffers’ strike was not protected under the law, a point disputed by the staff union.

“To best protect the interests of our members, the Association, and our staff, we have made the difficult decision to institute a protective lockout,” the spokesperson said.

The plans for the lockout were first reported by Education Week.