Consolidated Edison and its union workers returned to the bargaining table Friday but late that day union leaders told reporters in Queens that contract talks remained stalled.

At a hastily arranged press conference Friday night at the Courtyard Marriott Hotel in East Elmhurst, Queens, the union leaders said nothing substantive had changed and that the utility was acting "irresponsibly."

Workers have been locked out since Sunday, and since then, 5,000 managers have been working to keep the power flowing.

Employees said the utility was not bargaining in good faith.

"The union went in here with an open mind, hoping we could resolve this issue and move forward," said Paul Albano with UWUA Local 1-2. "The word that I got was that management didn't want to budge on any of the stuff. They were standing fast and not moving an inch on anything."

"As long as the talks are going on, that's a good thing but we reserve all details to the bargaining table," said Michael Clendenin of Con Edison. "We want both sides to come to a mutual agreement."

The utility said it offered a two-week extension of the old contract but was turned down.

The contract talks, which are expected to last through the weekend, come as air conditioners continue to put a strain on the power grid.

Con Ed has reduced voltage by 5 percent in more than a dozen Brooklyn neighborhoods and 11 neighborhoods in the southeast Bronx.