Ontario's Premier Dalton McGuinty is set to announce details on his full-day kindergarten at a news conference in Chatham on Tuesday.

CTV News has learned that nearly 600 schools will offer full-day learning for up to 35,000 children aged four and five.
Every school board in the province will have at least once school offering the full-day program, which will run five days per week.

McGuinty first unveiled his plan in late October. By 2011, the province hopes to have 50,000 kindergarteners taking part in all-day schooling. However, the program won't be mandatory.

By the time the program is fully implemented in 2015, it's estimated it will cost $1.5 billion per year. The province will spend $500-million on its two-year startup effort.

Under the plan, a teacher and an early childhood educator will preside over a class of 26 students.

The full-day session will run from 9 a.m. to 3:30 p.m. There will also be before- and after-school programs led by early childhood educators. While those daycare programs will not be free, there will be subsidies for families that cannot pay.

The government has said about 25 per cent of the province's schools already have the space available to accommodate the program.

The government will post a list of the schools online on Tuesday at about noon. Government MPPs will also be making announcements.

B.C. is another province moving in this direction.  In Nova Scotia, New Brunswick and Quebec, five-year-olds attend kindergarten all day. Quebec, Manitoba, Saskatchewan and Alberta have some programming for four-year-olds.

Ontario's move was prompted in part by a report released last June that said children who attend full-day programs prior to Grade 1 fare better academically and socially. About 18,000 students in the francophone and Catholic systems already get full-day kindergarten.

However, the move comes as Ontario wrestles with a deficit of nearly $25 billion. The Conservative opposition has said the province cannot afford the program.

On Monday, Tory education critic Elizabeth Witmer repeated her party's call that implementation of the program be delayed until the province is in better fiscal shape.

Witmer also argued that many low-income families, who are supposed to be the priority, won't be well-served because their schools won't have the room and the McGuinty government isn't providing the funds necessary to renovate.

A government spokesperson for Education Minister Kathleen Wynne said the government recognizes that some schools will require renovations, but no funding decisions will be made until spring.

NDP Leader Andrea Horwath said the government is offering full-day kindergarten while at the same time, funding is at risk for thousands of daycare spaces.

With a report from CTV Toronto's Paul Bliss and files from The Canadian Press