Hundreds of people gathered at Ottawa's Human Rights Monument Sunday to protest the Ford government's reversal of the province's sex-ed curriculum.

"Yes means yes, no means no," they chanted in unison. 

The afternoon rally was organized after Ford announced he was reinstating a 1998 sex-ed curriculum, repealing the existing program that includes education about oral sex, trans rights and consent. 

Upset over the changes, former NDP candidate Lyra Evans says they will run for school board trustee in zone 9, Rideau-Vanier/Capital. 

"I promise to fight back against Doug Ford’s decision to repeal the modernized sex ed curriculum. I will fight until all kids receive comprehensive sex ed," they wrote on Twitter.  "I went to school under Ontario’s old sex ed curriculum, and it didn’t teach me about consent or queer relationships. It didn’t teach me anything about consent or navigating gender identity. The old curriculum failed me and it will continue to fail students."

Ford's decision has sparked widespread criticism across the province. 

Andrea Horwath called on Ford earlier in the week 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in by the previous Liberal government, saying the 1998 version it was being temporarily replaced with was woefully out of date.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.

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.

Many at the protest highlighted the need for education about cyberbullying, sexual assault and consent due to increased access to social media and the internet. They also said children deserve to learn about same-sex marriage, and gender identity. 

With files from the Canadian Press