The Ontario government will tell anyone who asks, that Ontario has a publicly-funded Roman Catholic separate school system because it is in the Constitution. This was true in the past, but under the present circumstances, this argument does not hold up.
Besides, the Ontario government may change its perceived school funding obligation by passing a Bill in the Legislature to that, effect because the Constitution gives the provincial government absolute power over education. The proof of this statement is the fact that Manitoba did this in 1890 and the so-called “guarantee” for school funding remains in the Constitution for Manitoba to this day.
However, when Quebec and Newfoundland & Labrador wanted to get rid of church control over education, they both opted to use the Constitutional amending formula, section 43, which allows a change within a province’s own boundaries without any approval being required by other provinces. Such a decision for change by a provincial legislature needs only the approval of the House of Commons and the Senate.
It should also be noted that the House of Commons and the Senate , as well as the provincial legislature, may also institute constitutional change. So the federal government could adhere to its obligation under international law to eliminate religious discrimination in the Ontario school systems by initiating a constitutional change to that effect. And so could the Senate. There are unscrupulous politicians everywhere.
On the right-hand-side in red type, check out the story of each province which has used the legal provisions available to rid their laws of religious discrimination. These same legal provisions are available to Ontario.