If Portland teachers go on strike, the school district plans to keep schools open with substitutes.
KATU reports the subs are represented by the same union as regular teachers, but with separate contracts.
The Portland Association of Teachers says it filed a grievance Tuesday with the Oregon Employment Relations Board, complaining that the district is threatening to retaliate against subs who won't cross picket lines.
Portland Public Schools spokeswoman Christine Miles says the accusation is false and the district is not bullying anyone. But, she says, their contract requires subs to be available if teachers strike.