Anti-LGBT activists have filed a lawsuit against the public library in Texas over an event involving drag queens.

In the lawsuit filed on Friday (October 19) against the director of Houston Public Library and Mayor of Houston Sylvester Turner, anti-LGBT activists allege that the drag queen story time events violate the US Constitution’s religious freedom protections.

The Houston Chronicle reports that the lawsuit was filed on behalf of a group of self-described “Christ followers” who accused the library of promoting a “LGBT doctrine,” alleging unequal treatment because a “man-woman marriage storytelling hour” would not be permitted.

In August, Houston Public Library joined a growing wave of libraries across the world inviting local drag queens to come in and read story books to children, with the aim of promoting literacy and inclusivity.

The events are hugely popular with kids, but have invited attacks from religious groups and anti-LGBT conservatives.

A spokesperson for the library told PinkNews: “The city considers this lawsuit to be frivolous.”

Event listings on the Houston Public Library website show that further Drag Queen Storytime events are set to go ahead at Houston’s Freed-Montrose Neighborhood Library on October 27 and December 29.

The listing states: “Break out the dress up chest and let your imagination run wild as you join the Houston Public Library and local Drag Queens for storytime.

“These vibrant Queens will help to instill a sense of love and acceptance in our children while encouraging them to be true to themselves.”

The lawsuit was filed by Chris Sevier, an anti-LGBT campaigner who has filed a wave of similar lawsuits.

In September he filed a lawsuit against Lafayette Library in Louisiana over a drag queen story time event.

Sevier has also filed lawsuits in multiple states seeking the right to marry inanimate objects such as a laptop.

The activist, who is not a registered lawyer, was arrested on charges of stalking country music star John Rich in 2013.

Houston has been a prominent battleground for LGBT+ rights, as a liberal city in a traditionally-conservative state.

The city made history in 2010 when it elected lesbian Mayor Annise Parker, who was among the first out mayors of a major US city.

Mayor Parker passed an LGBT+ rights ordinance in the city, but in 2015 the law was struck down by voters after a campaign targeting transgender people’s bathroom use. At the time, it was one of the first instances of the ‘bathroom debate’ being used to roll back LGBT+ rights.

The activist behind the library lawsuit, Sevier, has close ties to a number of state-level Republican lawmakers, penning proposed legislation that was submitted by GOP officials in two states.

Eight GOP lawmakers sponsored Sevier’s proposed Marriage and Constitution Restoration Act bills in South Carolina and Wyoming earlier this year.

The bills appeared to be an attempt to segregate same-sex marriage from heterosexual unions in the wake of the 2015 Supreme Court decision that brought equal marriage to all 50 states.

The proposed laws sought to define “any form of marriage that does not involve one man and one woman” as a “parody marriage” and block legal recognition of such unions.

In South Carolina, the bill was sponsored by six Republican lawmakers, Steven Wayne Long, Bill Chumley, Mike Burns, John McCravy, Josiah Magnuson and Rick Martin.

An identical bill in Wyoming was sponsored by GOP lawmakers Lars Lone and Roy Edwards.