Ontario NDP leader Andrea Horwath says Premier Doug Ford’s decision to revert back to the old sex-ed curriculum will hurt the province’s children.

“To state the obvious, Doug Ford is absolutely wrong to rip up the health and physical education curriculum and drag Ontario back to the 1990s,” Horwath said.

Horwath said the 20-year-old version of the curriculum is badly out of date, making no mention of things like same-sex marriage or the Internet or social media.

“A race back in time will only put students at risk and deny young people the supports, the dignity, the equality that they deserve,” she said.

She made the comments Friday, at an event where advocates were speaking out in support of the updated curriculum put in place by the Liberal government in 2015.

Doug Ford is forcing a sex ed curriculum into classrooms that was written before same-sex marriage was legal. Heading down to @the519 right now to make sure LGBTQ+ youth know #wehaveyourback #onpoli pic.twitter.com/U8pguKZT6m

— Andrea Horwath (@AndreaHorwath) July 13, 2018

The Elementary Teachers Federation of Ontario president Sam Hammond says the move is a “huge disservice” to students, who need to learn about critical issues such as consent.

In Thursday’s throne speech, the Progressive Conservatives promised to replace what it called “failed ideological experiments in the classroom” when it comes to math and sex-ed.

The government announced teachers would use the 1998  sex-ed curriculum come September, as consultations are carried out for a new curriculum.

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

Critics of the new curriculum were unhappy with the inclusion of some topics including same-sex marriage, gender identity and masturbation and at what age they were taught.