"It was inadvertent ... and if anybody wishes to challenge that in the house they have the right to do that," Selinger told reporters.
"You answer the questions accurately the best you (can) at the time, and this specific piece of information was inadvertently omitted."
The apology comes a few days after it was revealed, in an anonymous email sent to several media outlets, that Selinger had attended a Winnipeg Jets game in December 2011 with Saskatchewan politician Ken Cheveldayoff.
That contradicts what Selinger said in May 2012, when his government was facing criticism after several cabinet ministers accepted free Jets tickets from both public-sector agencies and private firms. Selinger released a list of 13 NDP caucus members who had received the free tickets. His own name was not on the list.
That same week, Selinger was asked by then-Opposition leader Hugh McFadyen whether he had received any free Jets tickets.
"No," said Selinger, according to the official transcript of a legislature committee hearing.
"So did the premier directly purchase his tickets, then, from the Jets box office?" McFadyen asked.
"I directly purchased my own tickets, yes," Selinger responded.
"And were they purchased directly from the Jets organization?" McFadyen continued.
"Yes," Selinger said.
After the truth was revealed this week, Selinger said he wanted to pay for the ticket, but his host didn't want the money, so the premier gave $300 to charity about six weeks later.
Brian Pallister, leader of the Opposition Progressive Conservatives, said the timing of the premier's apology is questionable.
"It's late in coming, but it is an apology, and I was raised to believe you accept it when people offer it."
Selinger's use of the word "inadvertent" could be key to avoiding any potential trouble.
Under the Legislative Assembly Act, anyone who misleads the legislature or one of its committees can be sanctioned and jailed. But previous rulings from the Speaker have established a precedent that no penalty is meted out if the misleading was inadvertent.
Stan Struthers, a former cabinet minister who resigned from the inner circle recently after questioning Selinger's leadership, apologized in 2012 for misleading the legislature by saying he didn't receive any free Jets tickets. It was revealed days later that he had received a few freebies.
Struthers apologized, and Speaker Daryl Reid ruled that Struthers committed no offence because his misleading statement was inadvertent.
Another former NDP cabinet minister, Christine Melnick, apologized in the legislature last year for misleading the house when she denied using bureaucrats to round up supporters for an immigration debate.
An ombudsman's report found Melnick was in fact behind the plan. Melnick said her misleading statement was inadvertent, prompted by memory loss associated with undiagnosed diabetes.
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