Left-wing political commentator Cenk Uygur and his nephew, Hasan Piker, have been denied entry to the U.K. by the government’s Home Office, The Hollywood Reporter has confirmed. It’ll mean they can no longer make their scheduled SXSW London appearances.

A rep for the Home Office told THR on Monday that the pair’s Electronic Travel Authorization (ETA) has been cancelled on the grounds that their “presence in the U.K. may not be conducive to the public good.” They added: “Decisions to refuse or cancel an ETA on these grounds are based solely on an assessment of the potential risk an individual may pose to U.K. Society.”

On social media, Uygur, host of populist political talkshow The Young Turks, said that he was banned for “criticising Israel.”

“I tried to get on a flight to London to attend SXSW London and give a speech at Oxford. I’ve been banned for criticising Israel,” he wrote. “Are we free anymore? This is oppression of Western citizens by our own governments on behalf of a different country.”

Piker responded to his uncle’s post, adding: “The U.K. has revoked my visa as well. All at the behest of Israel,” and saying the West is “betraying ‘liberal values’ for a genocidal fascist foreign government.” Both men have condemned Israel for its war on Gaza following Hamas’ October 7, 2023, attack at an Israeli music festival. Since then, 70,000 Palestinians have been killed, according to the Hamas-run health ministry.

According to The Times, the decision to block Uygur’s entry is understood to have been based on concerns his presence would risk “exacerbating antisemitism.” He has been accused of pushing antisemitic tropes through his platform, such as that “Israel controls America.”

The SXSW team describes Piker, who has over three million followers on Twitch and more than 1.5 million on X, as “redefining what political commentary looks like in the digital age.” He has previously said Hamas is “1,000 times better” than Israel and attracted criticism over his claim that he “would vote for Hamas over Israel every single time,” on an episode of Pod Save America.

Uygur was meant to appear at a SXSW London session on Wednesday edtitled “Techno-Feudalism is Here. Who Are the Lords?” Piker’s planned panel on Thursday was called “How the American Left Learned to Speak the Internet.”

Ash Sarkar, a journalist for Novara Media who was due to chair Piker’s SXSW London session, said on X that the decision was evidence of an “authoritarian turn motivated by Labour’s fear of being called antisemitic, and fear of being called out for their position on the genocidal war on Gaza”, adding: “You don’t foster community cohesion by having the government ban people from speaking.”

U.K.-based Jewish organization the Community Security Trust urged SXSW last week to “act responsibly” and not allow the U.K. to be a “platform” for Piker.

A spokesperson for SXSW London confirmed to THR late on Monday afternoon that the decision means Uygur and Piker will not be participating in their planned panels. They said: “We are aware that Cenk Uygur and Hasan Piker are unable to travel to the U.K. following a decision by the Home Office […] Decisions on entry to the U.K. are a matter for the Home Office and the individuals concerned. SXSW London’s role is to convene a broad range of diverse voices and perspectives.”

“We remain focused on delivering a programme this week [that] fosters open dialogue and [the] exchange of ideas and featuring more than 800 speakers, artists and screenings,” they added.

You might recall that Kanye West’s ETA was revoked shortly before he was set to headline the now-scrapped Wireless music festival in April, over the rapper’s historical antisemitism.