TORONTO - Premier Dalton McGuinty will announce Tuesday that it will take Ontario five years to phase in a much-touted plan to offer all-day kindergarten for all four- and five-year-olds, The Canadian Press has learned.

Some 35,000 kids -- about 16 per cent the eligible junior and senior kindergarten students in the education system -- will be offered full-day learning next September, but the program will be fully implemented across the province by 2015, a government source said.

That will put it behind British Columbia, which plans to make full-day kindergarten for all five-year-olds by 2011.

"Full-day kindergarten is all about building the skills and education of tomorrow's workforce," the government source said. "We're doing this because it will make Ontario's economy stronger."

It's unclear how many schools will offer the program and which cities may see it start up next year. But the five-year time frame is longer than expected.

McGuinty had previously warned that it could take more than three years to implement the plan, which will eventually turn some schools into one-stop family centres that include everything from daycare to employment services.

Ontario has set aside $500 million over two years to phase in optional, all-day kindergarten, despite an unprecedented deficit that's expected to reach $24.7 billion this fiscal year.

Similarly, British Columbia plans to spend $151 million to start up its all-day kindergarten for five-year-olds next year despite its $2.8-billion deficit. Only half of those kids will have the option of an all-day program next year, but the government wants it available to all kindergarten students by 2011.

New Brunswick, Nova Scotia and Quebec offer all-day kindergarten for five-year-olds. Alberta, Manitoba, Saskatchewan and Quebec offer some programs for four-year-olds. Ontario has part-day kindergarten for four-year-olds, but school is not mandatory until Grade 1.

The move has already drawn fire from the Ontario Tories, who say the province simply can't afford the program when it's staring down an unprecedented $24.7-billion deficit this fiscal year.

"We have the biggest deficit in the history of the province, we're spending $2.8 million more per hour, each and every hour of the day, than we're taking in in revenue -- you can't afford a massive new spending program," said Opposition Leader Tim Hudak.

"When families find their credit cards maxed out, and their bank accounts are empty, you don't go shopping for a new car. Similarly here -- we cannot proceed at this time."

Charles Pascal, the government's early learning advisor, had estimated that the fully implemented early learning program could cost about $1 billion.

His June report recommended sweeping changes that include expanding paid parental leave to 400 days, and combining daycare and kindergarten into a single full-day program from 7:30 a.m. to 6:00 p.m. to make life easier for parents and their children.

It also said that children who have attended full-day programs before Grade 1 fare better academically and have better social skills.

The logistics of the scheme are almost overwhelming. But Pascal said he's feeling "very positive" that Tuesday's announcement will mark a new beginning for the province.

"This is absolutely critical for the social and economic progress of our province," he said in an interview.

If you compare all-day kindergarten to other stimulus ventures like bridge-building and road repairs, the investment in children is the project that "keeps on giving," he said.

With early learning, children are better prepared for elementary school and parents seeking supports for their kids are no longer navigating a "fragmented" system, he said.

"There is no better return on a taxpayer's investment than early learning in terms of our future progress," Pascal added.

All-day kindergarten should be a priority for the Ontario Liberals because it would create a foundation for other positive changes in education, said Annie Kidder of People for Education.

"Economically, it does makes sense, even though we're in a recession," she added.

"In terms of actually getting ourselves out long-term of a deficit (and) providing more economic stability, investing in early childhood and education have the best cost-benefits of any government investment."

In June, McGuinty said he planned to use the all-day learning plan to help his government's anti-poverty efforts by starting the program in lower-income neighbourhoods. Priority would also be given to schools with declining enrolment because they have space for additional students.

Parents would still have a choice about whether their four- and five-year-olds would be enrolled for a full or half-day of kindergarten, or nothing at all.

He also favoured having teachers work alongside early childhood education specialists, even though teachers' unions have balked at that idea.

The Elementary Teacher's Federation of Ontario has said it rejected Pascal's notion of replacing qualified teachers in kindergarten with staff that have "lower credentials."

The important thing is that all adults involved have expertise with teaching young children, said Pascal.

"I'm quite confident that teachers and early childhood educators, for the sake of kids and families, will play nice in the sandbox together," he said.