The president of the largest utility company said it’s working to turn the lights back on for the approximately 740,000 customers still in the dark Monday evening. But don’t expect them to come back on anytime soon.

Jeffrey Butler, president and CEO of Connecticut Light & Power, said about 831,000 customers were without power this past Sunday afternoon and while he expects the pace of restoration to speed up over the coming days a vast majority may not have power until next Sunday.

Restoring power within a week of the outage, “That’s what we’re working to achieve,” Butler said at a Monday evening briefing with Gov. Dannel P. Malloy.

Butler said the priority for his company remains the transmission lines. He said there are still about 18 transmission lines down.

Transmission lines deliver the electricity to the substations, which then distribute it to the customers if there’s no break in the grid along the way.

The company has 314 line crews and 185 tree crews currently working to get power restored to the nearly 60 percent of the state that’s been without it since the weekend.

Butler said based on the mutual aid commitments he expects the number of crews working to solve the problem to increase to 845 total crew members Tuesday. He said that number does not include United Illuminating crews expected to join CL&P in their recovery efforts after finishing up their own. By late in the week a total of 1,259 crews are expected to join the effort, but Butler said the company is still looking for about 350 line crews and 168 tree crews to help them complete the work. 

“Trees are the single biggest issue once again that has affected electrical reliability in the state of Connecticut,” Butler said.

In addition to many spending the next few days in the dark, many may have been unable to get out and register to vote for the Nov. 8 municipal election.

Malloy said he took it upon himself to sign an emergency order extending the registration deadline until noon, Nov. 7.

“I don’t believe anybody should lose the right to vote as a result of a storm,” Malloy said. “I understand this will cause some inconvenience but protecting peoples’ rights to vote, I believe is the more important thing to do.”

He said some town halls weren’t open today and Tuesday, Nov. 1 was the deadline to register.