NDP Leader Andrea Horwath says Premier Doug Ford is repealing Ontario's modernized sex-education curriculum to please social conservative supporters, a move that she says will hurt the province's children.

Horwath made the comments at an event on Friday where advocates spoke out in support of the curriculum put in place in 2015 by the former Liberal government.

Earlier this week, the Tory government said teachers will use the 1998 version of the sexual-education curriculum in classrooms this fall as consultations are carried out for a new curriculum.

Horwath says the 20-year-old version of the curriculum is badly out of date and contains no reference to things like same sex marriage, the Internet or social media, and doesn't reflect the reality of modern society.

She says Ford must stop catering to social conservatives and keep the 2015 version of the document.

Ford repeatedly pledged to repeal and replace the curriculum during the spring election campaign, saying parents had not been consulted enough on its contents.