"Con Ed locked out members at 2 a.m.," said John Melia, spokesman for Local 1-2 of the Utility Workers Union of America.
Melia said the union was willing to continue talks on a new contract but had been rebuffed when it requested the company set a date for a new bargaining session.
The New York Times said Con Ed was deploying 5,000 supervisors to maintain service while the union members were off the job.
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