(Providence, RI) -- The Providence Teachers Union is warning Mayor Jorge Elorza's administration of possible labor action if scheduled contract negotiations with the city on Thursday are not fruitful. Union president Maribeth Calabro says members have overwhelmingly voted to authorize work-to-rule, which means teachers will do the minimum amount of work required by their contract. Teachers have been working without a new deal for two years. Elorza's office responded by saying work-to-rule will negatively impact students.