TORONTO -- Progressive Conservative Leader Patrick Brown is promising to scrap the Liberals' sex-ed curriculum if his party forms government after the 2018 election.

In a letter distributed this week -- with days to go before a byelection in the east Toronto riding of Scarborough-Rouge River -- Brown wrote that "a PC government would scrap the controversial changes to sex-ed introduced by Premier (Kathleen) Wynne and develop a new curriculum after thoughtful and full consultation with parents."

The curriculum was updated last year, for the first time since 1998, to include same-sex relationships, and the dangers of online bullying and sexting.

But parts of the curriculum were controversial for some parents, who complained that the government should have consulted them more. Other were angered by mentions of same-sex relationships, gender identity and masturbation.

The changes prompted some parents to protest and even pull their children from public school, saying the new program is not appropriate for school-aged children and does not align with their values.

Brown told The Canadian Press in an interview in June that he would not repeal the curriculum if elected.

"But what I would say is that I do want to see our curriculum updated," he said at the time. "I want to have a greater emphasis on financial literacy in a more robust fashion. I'm very interested in the practical implications of having coding added to the curriculum."

Brown does not identify in the letter any changes he would like to see to the sex-ed curriculum, but says that reading, writing and math are all parts of a "well-rounded curriculum."

"I believe sex-ed is important, but it cannot be significantly changed without extensively consulting the primary educators of children, who have always been parents," he wrote.

During the party's leadership race last year, Brown spoke at a rally protesting the sex-ed curriculum, saying, "Teachers should teach facts about sex education, not values," without identifying what parts of the curriculum he felt were teaching values.

A spokeswoman for Education Minister Mitzie Hunter said scrapping the current curriculum would put young people at risk.

"Our students deserve an up-to-date, research-based curriculum that provides them with the knowledge and skills to stay healthy and safe in today's complex and ever-changing world," Nicole McInerney said in an emailed statement.

"The previous curriculum was more than 15 years old - dangerously out of date - and Ontario was behind provinces such as Alberta and BC in teaching about topics like online safety, healthy relationships and consent."

The provincial Liberal party issued a statement late Friday accusing Brown of flip flopping on his earlier position.

"Only Patrick Brown knows what he truly believes, if he believes in anything. Patrick Brown is an old-style politician who just says whatever he thinks people want to hear," the party statement said.

The NDP said in a statement Friday that it was time to update the curriculum to keep kids safe, and "going forward, it's also important for the government to engage in ongoing dialogue with parents and education professionals to ensure the curriculum remains up-to-date."