The Chicago Teachers Union filed a complaint Thursday against the Chicago Board of Education over the district’s efforts to extend the school day by 90 minutes.

More on longer school days

The complaint, filed with the Illinois Educational Labor Relations Board, alleges that Chicago Public Schools is violating its contract with teachers by trying to negotiate with individual schools rather than with the CTU to lengthen the school day.

In its effort to get teachers school by school to accept a longer day, the union says CPS “offered them inducements, threatened them with layoffs and monitored their private communications with the Union.” At one school, the union says teachers were promised iPads and off-the-books days off if they agreed to a longer day.

CTU wants the board to put a stop to school-by-school votes over the longer day, which it calls “sham” elections.

Read the complaint below under “EXTRAS.”