NEW YORK – About 1.9 million homes and businesses remained in the dark on Sunday as pressure mounted on power companies to restore electricity to areas hit hardest by Hurricane Sandy nearly a week ago.

In New York, utilities came under increasing calls to restore heat and light to some 650,000 customers. More than half of those were served by the Long Island Power Authority, which was singled out for criticism by Gov. Andrew Cuomo.

In New Jersey, about a quarter of the state remained without power.

After a peak of 8.5 million customers without power across 21 states affected by the massive storm, the rate of restoring power each day has slowed as line crews face increasingly difficult and isolated outages.

By Sunday afternoon, 640,000 customers had been switched back on in the last 24 hours, down from about 1 million who had power restored a day earlier.

After last year’s Tropical Storm Irene, most power was back within five days.

LIPA, which said Sunday afternoon it still had 370,000 of its 1.1 million customers without power, has come in for some of the toughest criticism over its efforts, particularly with a new cold front now menacing the region.

New York Governor Andrew Cuomo’s website put LIPA’s outages closer to 313,000 as of Sunday evening. That was the most of any utility serving the state. Con Edison, which serves about 3.3 million customers in New York State, was second at just under 200,000 customer outages.

Speaking at a press conference on Sunday morning, Cuomo again criticized LIPA’s restoration efforts and vowed to hold power companies “100 percent” accountable for their performance during restoration efforts.

Earlier this week, New York Mayor Michael Bloomberg had joined in the criticism, saying LIPA “has not acted aggressively enough” to restore power to customers. The utility’s New York City customers reside in Queens.

Local residents likewise expressed frustration with LIPA’s restoration efforts.

Tab Hauser, deputy mayor of the still-dark Village of Flower Hill on the north shore of Long Island, said that not only has the clean-up been too slow, LIPA “is doing nothing to prepare for the future.” He would like to see the utility consider underground lines and metal rather than wood poles. “Every year it’s a band aid,” he said. “This can happen next year and nothing will change.”

LIPA spokesperson Mark Gross was not available for an interview Sunday evening. However, he said in an email that the utility expected to have 90 percent of its customers restored by Wednesday evening. The remaining 10 percent, which includes areas devastated by flooding, would take longer.

THE LABOR-INTENSIVE STUFF

Nearly a week after Sandy’s landfall, industry experts warned that the overall pace of restoration might slow as utilities move to repair lines and poles that affect smaller numbers of customers.

“That’s the real labor-intensive stuff that it’s just street-to-street, house-to-house, neighborhood-by-neighborhood,” said Brian L. Wolff, senior vice president of external affairs at Edison Electric Institute, an industry group.

He added that some 150,000 to 200,000 customers “have such a level of physical destruction that they won’t be able to restore electricity for quite some time.”

In New Jersey, where many coastal towns experienced severe devastation, about 25 percent of utility customers were still without power on Sunday, according to the Department of Energy. Public Service Enterprise Group (PSEG) and Jersey Central Power & Light (JCP&L) – two major providers – each had about half a million customers without power.

PSE&G, which provides power to about 2.2 million customers across a wide swath of central New Jersey, said 493,000 were still without power as of Sunday morning. But critical infrastructure serviced by the utility already had its power restored, PSE&G President and Chief Operating Officer Ralph A. LaRossa told reporters on a conference call Sunday.

About 78 percent of gasoline stations had power restored, as well as 80 percent of schools, LaRossa said.

POLLING PLACES

Seven power substations, including six in Hudson County, were still being repaired, and the utility was busy coordinating power restoration efforts with local authorities for polling places in time for Election Day.

“We’ll be in pretty good shape by Tuesday,” LaRossa said.

JCP&L, which provides power to 1.1 million customers in 13 New Jersey counties, had 473,000 customers without power as of Sunday afternoon. That’s the vast majority of the 551,000 customers JCP&L’s parent company, energy provider FirstEnergy, reported across all its affected service areas.

In service areas outside of New Jersey, which include Maryland, Pennsylvania, West Virginia and Ohio, FirstEnergy expected to have service restored to the majority of polling places ahead of election day, Jennifer Young, a spokesperson for FirstEnergy, said in an email.

In Pennsylvania, power provider PPL Corp. was zeroing in on its remaining outages. Power had been restored to all polling places and schools in the utility’s 29-county service zone, spokesperson Michael Wood said. The company had about 15,0000 customers still without power as of late Sunday, he said

“Nearly all of those customers will be repaired today,” Wood said.

BRACING FOR THE WORST

But weather continued to complicate restoration efforts on Sunday as cold weather set in throughout the region, plunging temperatures and raising concerns about those still without light and heat.

Meteorologists also predicted that another “Nor’easter” – a coastal storm capable of producing strong winds and heavy rain – could hit the region by-midweek.

“It certainly can have an impact on slowing our crews that are making restorations,” John Miksad, Con Edison’s senior vice president of electric operations, told reporters on a conference call Sunday. The storm could also cause additional outages, he said.

Con Edison had about 198,000 customers without power as of late Sunday afternoon, Miksad said. Of those, 86,000 were located in Westchester County, 54,000 in Queens, 23,000 in Brooklyn, 19,000 in Staten Island and 11,000 in the Bronx. About 5,000 Con Edison customers in Manhattan also lacked power.

Con Edison aims to restore power to most of its customers by Friday.

(Additional reporting By Jilian Mincer and Robin Respaut; Editing by Jonathan Leff, Marguerita Choy and Ken Wills)