They took a break over the weekend.
Negotiations between the power company and Local 1-2 of the Utility Workers of America have been going on for weeks. The contract expired more than a week ago.
The union represents about 8,500 workers. Con Edison has more than 3 million customers and has been using managers in the field.
A union spokesman has said the bargaining is looking grim. Both sides say there are still many sticking points, including changing pension terms.
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