A prominent “ex-gay” therapist says a proposal to ban the widely discredited practice in Dallas would ruin the lives of his teenage clients.

David Pickup (right), who erected a billboard (above) promoting his business in Dallas last year, only to have it taken down by the advertising company, identifies as “ex-homosexual” and was a plaintiff in an unsuccessful lawsuit challenging California’s ban on reparative therapy. Pickup also wrote the background materials in support of the Republican Party of Texas’ platform plank endorsing reparative therapy.

Now, Dallas LGBT advocates are pushing for the city to become the first in Texas and only the fourth in the nation to outlaw reparative therapy. Pickup told The Texas Observer the proposed ban would harm “children who were emotionally and sexually abused who deal with homerotic feelings because of that abuse.”

“They’re obviously going to receive an intense fight against that,” Pickup said. “I don’t care about my business. My priority is my clients who are minors. It will no less than ruin their lives, and I do have significant numbers in Texas of these clients that deal with these issues.”

The city of Dallas’ LGBT Task Force is set to discuss the proposed reparative therapy ban in August, before forwarding it to the City Council.

Rafael McDonnell, a representative from Dallas’ LGBT community center, said the proposed ban would be in line with the city’s comprehensive resolution in support of LGBT equality, which was approved by the council in 2014.

“It is a critical issue in terms of our youth,” McDonnell said. “This is the snake oil of the 21st century.”