Human rights lawyers have announced a legal challenge of the Progressive Conservatives' plans for the sex-ed curriculum in Ontario.

At a press conference at Queen's Park Thursday morning, lawyers said they will use a section of the Ontario Human Rights Code which provides protection from discrimination in services.

"We'll be challenging it under gender expression, identification, sexual orientation, and gender," said Marcus McCann, one of the human rights lawyers involved in the case.

The Ford government has stated that it will scrap the current curriculum and return to using the 1998 sex-ed program when school resumes in September.

We're loathe to see the curriculum be retracted - Sylvie Liard

It is a temporary measure as the government said it wants to develop a new curriculum.

Critics say the 1998 curriculum is out-of-date and incomplete.

"We're loath to see the curriculum be retracted," said Sylvie Liard, a mother of three, one of whom is a gender non-conforming child. Her family is one of several taking part in the challenge.

"It comes down to erasure," said Liard. "All of a sudden, a topic that was liberally spoken about, where everyone is included. We have books, we have examples. We're living this to all of a sudden we're silencing it."

Official Opposition supports the challenge

The opposition NDP is backing the case going to the Ontario Human Rights Tribunal.

Peggy Sattler is the NDP MPP for London West. "This case is urgent, and I hope these families will be successful,"said Peggy Sattler, the NDP MPP for London West and her party's critic on education.

"Parents speak passionately about the fact that the 1998 curriculum will mean that their kids do not have the information they need to stay safe. Doug Ford should listen to these families and do what's best for the children of Ontario," said Sattler in a statement to the media.

Ontario's Minister of Education, Lisa Thompson, was asked about the human rights challenge by reporters at Queen's park today.

"My response is I have every confidence in our teachers and they're going to be utilizing the curriculum that was last used in 2014 and they're going to be preparing students for the realities of today," said Thompson.

Request for expedited hearing

The lawyers said papers will be filed with the Human Rights Tribunal within the next seven days, along with a request to expedite the process.

"We think the jurisprudence before the tribunal going back now almost 20 years requires anyone who provides services to the public, and especially the government, to do so in a way that is non-discriminatory," said McCann.