TORONTO - Taking five years to complete Ontario's four-year high school curriculum "is okay" with the province's self-proclaimed "education premier" as long as students graduate in the end.

Seventy-two per cent of Ontario students graduated high school after four years in 2010, up from 60 per cent when the Liberal government was first elected in 2003, Premier Dalton McGuinty said Tuesday.

However, McGuinty didn't announce the 72 per cent figure on his visit to George Harvey Collegiate Institute in Toronto, saying instead that the graduation rate rose to 81 per cent. He didn't mention that includes students who take five years to finish high school.

"I prefer to say to young people if you take five years to graduate, that's okay by me, and you're still counted," he said.

"Some kids can do it in four years, some choose to do it in five years, some can only do it in five years. It doesn't matter to me as a parent, as a teacher, as a premier; I just want you to get it done."

Ontario was the last province to eliminate Grade 13, which ended after the 2002-03 school year, but the legacy of that five-year high school curriculum is still with us, said McGuinty.

"We still come largely from a culture where we had a five-year high school system in place," he said.

"If it takes a little bit longer ... we're very supportive of that. We're not going to put in place some kind of arbitrary standard that says you're somehow less because you didn't do it in four years."

The 81 per cent of Ontario students who graduated high school after five years is up from 68 per cent in 2003. The government's goal is to have an 85 per cent graduation rate.

The Opposition said McGuinty wanted to show the highest possible grad rate in advance of the Oct. 6 election, and complained he had watered down the standards Ontario's high schools.

"I think the premier needs to be more clear on what those stats are instead of trying to boost them up in a pre-election period," said Progressive Conservative Leader Tim Hudak.

"Dalton McGuinty has lowered the bar by taking away report cards that parents count on, by making it easier to pass the standardized tests, and teachers can't even give zeros for missing or late assignments. I think that's wrong."

The New Democrats accused McGuinty of painting too rosy a picture on the graduation rate, and said many who do graduate will have trouble going to college or university because tuition is so high.

"I think we really have to be concerned about those one-in-five children who are still not graduating from high school," said NDP Leader Andrea Horwath.

"We know what that means in terms of their prospects for the future."

Statistics Canada measures graduation rates by looking at people in specific age groups who have a high school diploma.

The agency said by the ages of 18 to 19, the great majority of young people in all provinces had graduated from high school, ranging from 81 per cent in Newfoundland and Labrador, and 80 per cent in Quebec and British Columbia, to a low of 68.5 per cent in Nova Scotia.

The national average grad rate in the late-teen age group was just under 77 per cent.

On another education topic Tuesday, McGuinty suggested the Liberal government's promised consultation with parents on a new sex ed curriculum would not be done before the fall election.

The Liberal's revised sex ed curriculum was withdrawn a year ago after opposition from some groups, and the New Democrats say McGuinty is still running scared.

"It seems to me they're dragging their feet on this," said Horwath.

"In an election year, that's what you're going to see on those hot files."