A showdown between conservative and liberal state activists over the district’s proposed sex education curriculum is expected at Monday night’s Austin school board meeting.

Planned Parenthood of the Texas Capital Region is advocating for the district’s new curriculum, and on Wednesday asked supporters to join it in the board room to advocate for the new lesson plans, describing them as "LGBTQ inclusive, science-based, and much-needed."

Meanwhile, members of conservative, religious advocacy group Texas Values, which has lobbied against the new lessons in recent months, also plan to attend again, describing the lessons as "radical, sex-education curriculum that is wildly inappropriate." The group says it has collected 5,000 signatures on a petition against the curriculum.

The school board is slated to vote Monday on the new sex education curriculum for grades three through eight, which for the first time would introduce lessons to elementary students on gender identity, sexual orientation and sexually transmitted diseases.

District administrators said the shift in the new curriculum is aimed at focusing on issues of consent, as well as being more inclusive of LGBTQ students. While embraced by some district families, others have been rankled by the charges.

David Walls, a parent and the vice president of Texas Values, said he opposes the new lessons and also has problems with videos included in the curriculum, which he said encourages young children to engage in same-sex relationships.

"It’s not appropriate for school," Walls said. "It’s not appropriate for a government body to encourage students to engage in any kind of sexual activity."

The revised middle school lesson plans, which were made public last month for parent review, are a combination of materials created by the district, Canadian health service providers and other sources. They will be presented to the school board for the first time on Monday night. New lessons for younger grades are expected as early as next year.

Trustees already have signaled they plan to approve the curriculum. The board in February unanimously approved revisions to the district’s sex education curriculum standards, which made way for the changes to the actual lessons.

Included in the new curriculum for sixth graders is a "genderbread person," shaped as a gingerbread man, tagged with labels pertaining to one’s sexuality: (gender) identity pointing to the brain, attraction pointing to the heart, expression pointing to the body, and biological sex, pointing to the genital region.

The sixth grade lesson asks students to differentiate among gender identity, expression and sexual orientation, and describes gender identity as a "person’s internal sense of identity as female, male, both or neither, regardless of their biological sex assigned at birth."

Similar lessons are being taught for the first time in elementary school grade levels. It’s the first time the district has revamped its "Human Sexuality and Responsibility" curriculum for elementary students in a decade and for middle-schoolers since 2012.

"Our policy has changed to ‘all means all,’" said Michelle Rusnak, the district’s health and physical education supervisor. "We want to make sure that LGBTQ students are represented in our lessons. It’s about acceptance."

But after pushback from parents, the district chose to delay introducing such topics as sexual orientation and HIV until fifth grade (administrators previously recommended it be taught in third). Most recently, district administrators removed anal sex from a lesson about HIV and STD prevention, according to board documents, though the term, as well as oral sex, still appears in a list within the "Is this abstinence?" activity. Administrators also eliminated from the lessons a video called "Love is Love," which featured gay and mixed-race couples.

The proposed sex education curriculum has experienced multiple hiccups along the way. In the spring, a couple filed a grievance against school district staffers and the School Health Advisory Committee that involved the development of a revised sex education curriculum. Then this summer, the district had to nix plans for its middle school curriculum after the Legislature passed a law prohibiting local governments from doing business with abortion providers or their affiliates. While administrators had written their own elementary sex education curriculum, they opted to use middle school lessons developed by the Planned Parenthood League of Massachusetts. That sent administrators back to the drawing board in creating new middle school lessons.

Texas law requires schools that offer sex education to promote abstinence as the preferred behavior for unmarried students. The districts could address contraception but can’t distribute condoms, according to state law.

Austin is among 17% of Texas school districts that teach "abstinence-plus," which encourages abstinence, but also teaches other methods to prevent pregnancy and sexually transmitted diseases.