A group of protesters opposed to transgender rights disrupted Saturday's the Pride in London parade.

The small group lied down on the ground at the front of the march while carrying signs which read “transactivism erases lesbians” and “lesbian not queer,” forcing organizers to allow them to lead the parade.

London Mayor Sadiq Khan was supposed to lead the parade but was stuck behind the protesters for much of the route.

In a statement issued to PinkNews, Khan condemned the protesters.

“Pride is about celebrating difference and London's amazing LGBT+ community,” the mayor's office said.

“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.”

“Transphobia is never acceptable,” the statement added.

Jennie Rigg, chair of LGBT+ Lib Dems, told the Independent that she was “appalled” that the protesters were allowed to lead the march.

“This is a betrayal of the thousands marching,” Rigg said. “The Pride organizers should resign and offer a full apology.”

Organizers said that “hot weather” and safety concerns were behind their decision to allow the protesters to lead the parade.

According to the BBC, more than 1 million people watched the parade, with nearly 500 organizations participating.

(Related: Olly Alexander reminds London Pride revelers that Pride began as a protest.)