“Transactivism Erases Lesbians!” read a banner that temporarily led the Pride in London march in the heart of Britain’s capital. This banner naturally caused quite a stir, with London Mayor Sadiq Khan denouncing it in a statement.

“Pride is about celebrating difference and London’s amazing LGBT+ community,” Khan’s spokesperson told PinkNews. “It’s about showing those round the world that in our great city you can be free to be whoever you want to be and love whoever you want to love. The vast majority of those present at today’s march respected and embraced that and the Mayor condemns the tiny minority who did not.”

Who is that “tiny minority”? The final statement made it clear: “Transphobia is never acceptable.”

While Khan was meant to lead the march, he ended up stuck behind the group “Get the L Out,” a lesbian organization dedicated to separating lesbian identity from transgender identity. They started demanding that activists take the “T” out of “LGBT,” but settled for opting out themselves, demanding the “L” be removed.

Pride in London, the group behind the parade, gave various explanations for allowing “Get the L Out” to lead the way. An earlier statement suggested the organizations allowed the lesbian group, supporting their intent to protest. “As we found in our recent Pride Matters report, 24% of people say a Pride is protest. 78% said it was a celebration,” a spokesperson said.

In a second statement, the organizations pointed to the “hot weather” and a concern for the crowd’s safety in allowing “Get the L Out” to lead the parade. The organizers insisted they “do not condone” the group, although they did not condemn the lesbians.

“Given the hot weather and in the interest of the safety of everyone attending today’s event, the parade group was allowed to move ahead,” the organizers said. “We do not condone their approach and message and hope the actions of a very small number [of] people does not overshadow the messages of the 30,000 people marching today.”

Many activists have called for the organizers to resign. “I am appalled that transphobic protesters were allowed to lead the march and the crowd asked to cheer them on,” LGBT+ Lib Dems Chair Jennie Rigg said. “This is a betrayal of the thousands marching. The Pride organizers should resign and offer a full apology.”

Others attacked the sign on Twitter.

So, why do Jennie Rigg and Sadie Khan consider “Take the L Out” so “transphobic”? They disagree with transgender activism, but with an interesting twist. They’re not just the run-of-the-mill feminists complaining about biological males usurping the title of feminism. No, they accuse transgender activists of promoting conversion therapy and rape culture.