The Detroit Federation of Teachersis threatening a lawsuit that could force a legal showdown over Michigan's new teacher tenure law.
The union says Detroit Public Schools' process for re-hiring teachers this fall violates the union's contract.
The district has issued layoff notices to all its teachers. It will re-hire them based in part on performance evaluations.
Union President Keith Johnson says under its 2009 contract, the district and the union were supposed to come up with an evaluation tool together.
But Johnson says instead, district officials are now conducting what he calls "drive-by evaluations."
"It pretty much involves principals or even retired principals going into a teacher's classroom, staying for as little as four minutes, and then determining whether or not that teacher was effective, ineffective, minimally effective or whatever the case may have been."
Under Michigan's new tenure law, teachers are rated on a scale from highly effective to ineffective.
But Johnson says seniority can still be considered. He says if the district ignores that, he'll go to court.
A district spokesman says it's complying with the law and current collective bargaining agreements.
