Update: This story has been updated following statements from the U.K. Home Office and SXSW London.

The U.K. home secretary Shabana Mahmood has barred controversial Twitch streamer Hasan Piker and his uncle, broadcaster Cenk Uygur, from entering the U.K. The move means they will be unable to attend SXSW London, where they were scheduled to be speaking.

Reps for the Home Office confirmed to Variety that Piker and Uygur’s Electronic Travel Authorisation (ETA) had been revoked “on the grounds that their presence in the U.K. may not be conducive to the public good. 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.”

An ETA allows travelers to enter the U.K. without a visa for up to six months. The Home Office added that “Where applications require further consideration, individuals may choose to apply for a visa if they still wish to travel to the U.K.

In a statement on X, Uygur wrote: “I’ve been banned from the UK. I tried to get on a flight to London to attend SXSW London and give a speech at Oxford. I’ve been banned for criticizing Israel. Are we free anymore? This is oppression of Western citizens by our own governments on behalf of a different country!”

The social media personality responded to his uncle’s post with his own message, saying: “the uk has revoked my visa as well. all at the behest of israel. the west is betraying “liberal values” for a genocidal fascist foreign government. soon we will all become israel.” [Sic]

Piker was due to appear at SXSW London on a panel titled “How the American Left Learned to Speak the Internet” while Uygur was set to speak on “Techno-Feudalism is Here. Who Are the Lords?”

The Times of London reported Mamood’s decision was based on Uygur’s recent exchanges with Piers Morgan in which he made “concerning” comments about the U.K.’s grooming gangs scandal and that his presence would “risk exacerbating antisemitism due to his rhetoric since the October 7 attacks in 2023.” He has also denied the genocide in Armenia and is said to have made “misogynistic slurs” in the past.

Piker also has a history of making inflammatory statements, including saying that “America deserved 9/11″ and voicing support for proscribed terror group Hamas.

A spokesperson for SXSW London said: “We are aware that Cenk Uygur and Hasan Piker are unable to travel to the UK following a decision by the Home Office. They will therefore not be participating in the SXSW London programme this year. Decisions on entry to the UK 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 fostering open dialogue and exchange of ideas and featuring more than 800 speakers, artists and screenings.”