TORONTO -- Ontario's new sex-education curriculum retains many elements of a previous Liberal government document that the Progressive Conservatives had slammed as ideological, leading critics Wednesday to accuse them of playing politics with students' health.

When in Opposition the Tories largely stayed away from naming specific concepts in the curriculum that they had an issue with, but a protest movement led by social conservatives singled out gender identity, masturbation and references to anal intercourse as problematic.

In the new elementary curriculum, released Wednesday, sexual orientation will be a mandatory topic taught in Grade 5, earlier than in the Liberals' 2015 curriculum, which had it in Grade 6. Gender identity will be a mandatory topic in Grade 8 -- it was previously mandatory in Grade 6.

Education Minister Stephen Lecce said the new curriculum will also include a new focus on mental health, teachings on concussions and the risks of vaping, and expanded lessons on consent, cannabis risks and online safety.

"This is a transformed and updated, modernized curriculum with a central focus on safety," he said. "With great respect, in process and in substance, this is a dramatically better product."

Premier Doug Ford and other Tories had said the Liberal curriculum was ideological and had promised during last year's election to repeal it and engage in a wider consultation with parents. Some parents complained that the Liberal consultation, which reached out to a parent representative from each school, was not broad enough.

Once in power, the Tories scrapped the previous curriculum, implemented an interim one and launched an online consultation, which included various education issues, for around $1 million -- moves Lecce defended.

"There was not that support from the public from the old version," he said. "There just wasn't that social licence."

NDP education critic Marit Stiles said the premier spent much time and money playing a "political game."

"Doug Ford wasted a year playing politics with our kids' safety and well-being," she said. "And for what? So he could show off to social conservatives at the expense of our kids?"

Former Liberal premier Kathleen Wynne, who is gay, has said she had no doubt that homophobia motivated some of those who protested the old curriculum.

One of the most vocal opponents to the curriculum, Tanya Granic Allen, had vaulted the issue back into the spotlight when she ran for the Progressive Conservative leadership months prior to the election. She tweeted Wednesday that Ford's new curriculum is a betrayal.

"The radical Wynne sex-ed is still there - ALL OF IT. And gender identity is mentioned 40 times," Granic Allen wrote. "Ford LIED to the parents."

The government has said that teachers can use their professional judgment and can speak about topics such as gender identity if they arise in the classroom earlier than the curriculum mandates. Granic Allen said that means gender identity can be taught to kids in Grade 1 and "there's some topics you simply don't teach to children."

Interim Liberal leader John Fraser said Ford's promise to repeal and replace the sex-ed curriculum was only made to get social conservatives' support during the Tory leadership campaign.

"It was purely political," he said. "I'm happy that essentially the 2015 curriculum has been reinstated ... The bad thing is that it created a lot of instability in classrooms and in schools."

Elementary teachers took the government to court over the repeal, raising particular concerns with what they dubbed a "snitch line."

When some teachers said they would continue to use the updated teachings in the 2015 curriculum despite its repeal, Ford warned that the government would not tolerate anyone using children "as pawns for grandstanding and political games" and launched a now-defunct website where parents could report such concerns.

The Elementary Teachers' Federation of Ontario said it was pleased that topics such as consent, sexting and gender identity remain in the curriculum, though they were concerned gender identity lessons have been pushed back two years.

Both sexual orientation and gender identity were also previously mentioned in the curriculum document for Grade 3, though they were not mandatory lessons.

Students had to describe how visible and invisible differences make each person unique, and examples given for invisible differences were "learning abilities, skills and talents, personal or cultural values and beliefs, gender identity, sexual orientation, family background, personal preferences, allergies and sensitivities."

Those references to gender identity and sexual orientation have now been removed, and mental illness has been added.

Lecce said the lessons in different grades all build on each other.

"When it comes to visible and invisible differences, that remains in the curriculum to teach," he said.

Masturbation remains an optional teacher prompt in Grade 6, and anal sex continues to be first mentioned in Grade 7, in terms of delaying sexual activity until people are older.

There will also be an option for parents to have their children opt out of certain teaching blocks, which standardizes a process that was already in place across most of the province.