Florida Governor Ron DeSantis on Tuesday signed a law that bars transgender women and girls from competing in girls and women’s sports at public schools in the southern US state.

DeSantis signed the measure on the first day of LGBTQ Pride Month.

Also read: Why is June celebrated as Pride month? Know its history and significance

“We believe that is very important that the integrity of these competitions are preserved,” said the Republican governor as he signed the measure into law at a Christian school in the northeastern city of Jacksonville.

“In Florida, girls are going to play girls’ sports, and boys are going to play boys’ sports,” he said. “We’re gonna go based on biology, not based on ideology when we’re doing sports.”

The law, which goes into effect on July 1, requires girls and young women to state their biological sex through their birth certificate in order to compete in a team.

“First day of LGBTQ Pride Month and @GovRonDeSantis signs SB 1028 which bans trans kids from school sports… This fuels transphobia and puts vulnerable kids at risk for no good reason,” tweeted Florida state representative Carlos Smith, a Democrat who identifies as Latino and gay.

Also read: From ‘Eternals’ to ‘Spiral’, a look at Hollywood films that celebrate LGBTQ

The Human Rights Campaign, a group defending the rights of the LGBTQ community, announced said it would challenge the measure in court.

“Gov. DeSantis and Florida lawmakers are legislating based on a false, discriminatory premise that puts the safety and well-being of transgender children on the line,” wrote Campaign president Alphonso David.

“Transgender kids are kids; transgender girls are girls. Like all children, they deserve the opportunity to play sports with their friends and be a part of a team,” David said.

Florida now becomes the most populous US state banning transgender women from female sports, joining other states with Republican governors that have recently approved similar measures.