Some 30,000 households and other Newfoundland Power customers were still without power early Monday, the Canadian Broadcasting Corp. reported.
Authorities are looking into what caused blackouts Thursday, which were followed by more outages throughout the weekend due to a blizzard and fire at a substation that knocked out power to much of St. John's.
New Democratic Party Leader Lorraine Michael said she strongly disagreed with Premier Dunderdale's decision to call the situation in the province a serious challenge instead of a crisis.
"The people of the province believe there is a crisis," Michael said. "I wish the premier would start using the language of the experience of the people of the province. We have a crisis when we cannot meet peak moments during the year."
Opposition Leader Dwight Ball agreed with Michael.
"This is a crisis, there's no doubt about that," Ball told CBC News. "Any time that you have to take this kind of generation out of service in January, I would consider that a crisis."
Meanwhile, the province closed all public schools Monday and Tuesday, and said all government employees will be sent home at 5 p.m. to keep energy demands low.