The Human Rights Campaign (HRC), the nation's largest LGBT rights advocate, has responded to the passage of an anti-transgender youth sports bill in Texas.

Republican Governor Greg Abbott signed the legislation, House Bill 25, into law on Monday.

The law requires all transgender student athletes in grades K-12 to play on sports teams that correspond to the “biological sex” listed on their birth certificate.

Similar laws have been enacted in Alabama, Arkansas, Florida, Idaho, Mississippi, Montana, South Dakota (by executive order), Tennessee, and West Virginia.

HRC, which had called on Abbott to veto the bill, called Monday a “dark day” for thousands of families in Texas.

“This is a dark and frightening day for thousands of families in Texas who fear for the safety and future of their transgender children,” HRC Texas State Director Rebecca Marques said in a statement. “Transgender animus is on the rise in Texas and across the country as evidenced by discriminatory legislation, and this only serves to give fire to the hate we’re seeing. Transgender kids, just like any kid, simply want to play sports with their friends. They are being denied that chance by legislators whose arguments are not backed up by evidence, educators, medical consensus, or science.”

“This bill has always been a right-wing political 'solution' in search of a problem, as Governor Abbott and Texas legislators have failed to provide examples of any issues in the state because there simply are none.”

“Governor Abbott’s relentless pursuit of an abortion ban and anti-transgender legislation during multiple special sessions shows that he is more focused on appealing to a radical primary base than he is solving real problems like fixing the electrical grid against extreme weather. The Human Rights Campaign will use every tool in the toolkit to stop this law from taking effect and fighting to repeal this and every anti-transgender bill in the country,” Marques said.

Republicans approved House Bill 25 with the help of one Democrat, Senator Eddie Lucio Jr. of Brownsville.