PITTSBURGH — The Pittsburgh teacher’s union has voted nearly unanimously to authorize its leadership to call for a strike.

The city Federation of Teachers announced the result of the vote Monday night. Union members voted 2,309 in favor of a strike and 144 against.

Union President Nina Esposito-Visgitis says the vote indicates how strongly members feel about the current contract negotiations. Five-year contracts for union members expired in June 2015.

Esposito-Visgitis says members want reduced class sizes and increased support for early-childhood teachers among other requests.

The executive board will meet Thursday to decide how to proceed. Negotiations with the school district are scheduled for Friday.

Pittsburgh teachers last went on strike 40 years ago. Board members have to give 48 hours’ notice before striking.