TORONTO -- The leader of Ontario's Opposition said Friday that Doug Ford's decision to repeal Ontario's modernized sex-ed curriculum and replace it with a 20-year-old version was a move to please social conservatives and one that would hurt the province's children.

Andrea Horwath called on Ford to keep the 2015 iteration of the curriculum brought in by the previous Liberal government, saying the 1998 version it was being temporarily replaced with was woefully out of date.

"Doug Ford cares more about the favours that he owes to social conservatives than he does about keeping our young people safe," said the NDP leader, arguing that Ford was aiming to please those who helped him win the party leadership earlier this year.

"He made back room deals with far-right lobbyists to force this outdated sex-education curriculum on students."

Ford's office did not immediately respond to a request for comment.

Earlier this week, Ford's new Progressive Conservative government said teachers will use the 1998 version of the sex-ed curriculum this fall as consultations are carried out for a new document. The development made good on Ford's repeated promise to do away with the updated curriculum, which he said parents had not been adequately consulted on.

The 2015 sex-ed curriculum includes warnings about online bullying and sexting that were not in the previous version, and also discussed same-sex marriage, gender identity and masturbation.

Horwath said the 1998 version of the curriculum doesn't reflect the reality of modern society.

The Tories' plans on sex-ed were highlighted in Thursday's throne speech, which said the government would replace the Liberal curriculum with a "new age-appropriate one that is based on real consultation with parents."

Charles McVety, a vocal social conservative minister who supports Ford and had criticized the modernized sex-ed curriculum, lauded the premier for living up to his word to replace the lesson plan.

"He's really brought common sense to this," McVety said. "Go to the parents. Study this. Come up with a consensus. We'll end up with something that really helps children."

Former NDP legislator and United Church minister Cheri DiNovo, however, said Ford has aligned himself with a "fringe" group on the religious right.

"They do not speak for the people of faith across this country. They do not speak for Christians or Muslims or Sikhs or Jews or anyone else," said DiNovo, who plans to present Ford on Monday with a petition signed by 200 United Church ministers standing against the replacement of the sex-education curriculum.

Di Novo also said Ford's claim there wasn't enough consultation to build the 2015 curriculum isn't true.

"Some numbers -- 4,000 parents, 2,400 educators, 700 students, 170 organizations including CAMH over ten years went into writing this curriculum, so anyone saying there wasn't enough consultation is telling you nonsense," she said. "That is a lot of consultation."