The UK’s famously tough immigrations laws have claimed another scalp: Lauren Southern, the alt-right YouTube vlogger and political commentator.

On Monday morning, Southern tweeted that British authorities banned her from entering the country. “They just locked me out and said, ‘au revoir,'” Southern, who has long advocated for stricter European border controls, said. “Officially banned from UK for ‘racism.’”

In further tweets, Southern claimed UK border police detained her for “alleged racism” under UK terrorism laws. “At least they let me identify as Pakistani on my report lol,” she posted.

Never one to pass up a chance to insert herself into the conversation as a free speech warrior, British right-wing commentator Katie Hopkins posted an image of what appears to be an official document refusing Southern leave to enter the UK.

Hopkins—who once called for gunships to shoot migrants to protect the UK’s borders—accused British home secretary Amber Rudd of siding with Islamists: “You have detained @Lauren_Southern in Calais and prevented her entering the U.K. She is a Christian Conservative. You have sided with Islamists of Luton. You need to make better decisions ma’am.”

The irony of two staunch advocates of border control criticizing the British authorities for tight border controls has not been lost on many social media users.

“It’s funny because Lauren Southern advocates strict border control & denial of entry for people from other cultures whose beliefs don’t match with the host country’s 'values' but I guess she assumed since she’s white that shouldn’t apply to her lol,” wrote one user.

In May 2017, Southern was detained by the Italian coast guard after she attempted to block the passage of an NGO ship that rescued shipwrecked migrants off the shores of North Africa. The Barbarians: How The Baby Boomers, Immigration and Islam Screwed My Generation author has previously faked transitioning genders to mock transgender rights, and called Black Lives Matter a "divisive, violent movement that has fascistic tendencies."

Local newspaper Luton Today reports that Southern was denied entry to the UK after she was photographed in the Bedfordshire town displaying inflammatory posters that stated "Allah is a gay god."

Under British law, immigration authorities have the right to refuse entry to individuals if, among other reasons, they are believed to pose a security threat to the British public or are of adverse character.

The Home Office confirmed that Southern was refused leave to enter the UK on Monday morning. A spokesperson told Broadly: “Border Force has the power to refuse entry to an individual if it is considered that his or her presence in the UK is not conducive to the public good.”