Planned lessons on LGBT tolerance at a San Francisco Bay Area middle school have sparked outrage from parents who call the material inappropriate or insensitive to "those with religious, cultural and personal convictions not in agreement or acceptance with the promotional campaign."

Some parents whose children attend Windemere Ranch Middle School in San Ramon have launched a petition seeking to have the lessons limited to one day. Parents are also threatening a student walkout April 11, the day lessons are set to begin, if changes are not made.

"Inequalities in such efforts are evident when comparing the time, resources and intensity devoted to lessons, activities, and promotional fanfare dedicated to the acceptance of the Lesbian, Gay, Bi-sexual, and Transgender group while ignoring acceptance and promotion of values represented in other diverse groups within our community," the petition reads.

The lessons, set up by a student leadership group, are part of the school's second annual LGBT awareness week, which will feature lessons on safety and respect for all students with a specific focus on the LGBTQ community, the San Ramon Unified School District said.

The week leads up to the national Day of Silence — April 15 — meant to raise awareness of "the silencing effect of anti-LGBT bullying, harassment and discrimination," according to the Gay, Lesbian and Straight Education Network.

Some parents opposed to the lessons do not want a full week devoted to the topic.

"There is a time for everything in life. I don't think Middle school is the right time to expose kids to all this stuff," one parent wrote on the petition page.

Another parent commented: "This is a discriminatory action fully biased in support of a specific group and not taking consideration the diversity and religious views of our community."

In response to the backlash, students were allowed to opt out of lessons, which the principal revised and sent home to parents for review, according to the school district.

Parents are scheduled to meet with district officials on Friday.

School district spokeswoman Elizabeth Graswich on Thursday provided the following statement:

During the week of April 11, Windemere Ranch Middle School has planned a week of lessons around the theme of “acceptance.” The idea came from the school’s leadership students who wanted to plan lessons to address acceptance and respect for all leading up to the National Day of Silence on Friday, April 15. The lessons are on safety and respect for all students with a specific focus on the LGBTQ (Lesbian, Gay, Bi-sexual, Transgender, Questioning) community.

This is the second year in a row that the Leadership students have created and presented lessons on this theme. The presentations are part of the student leadership program. Throughout the year, each week, leadership students present “character education” lessons to their fellow-students. Other topics that they students have addressed include bullying, “Words Matter Week” and “Holocaust Teaching Week.”

This week, the principal, Dave Bolin, shared the intended lessons for the Week of April 11 with all the parents, in order to provide them an opportunity to review the lessons and choose to opt their children out. This is part of a common practice to provide parents an opportunity to review and opt out of lessons of a sensitive nature. Another example would be sexual education lessons.

Since sending the lessons to parents, the principal has received some feedback that has led to revisions to the lesson plans. A follow-up email was sent to parents today with the revised lessons for parents to review and provide input.