This article examines the development of anti-transgender debates within the United Kingdom, which have gained traction due to proposed amendments to the country’s Gender Recognition Act (GRA). A group of determined lobby groups, taking their lead from like-minded organizations in the United States, has protested vigorously against the proposed changes to the GRA, especially with respect to “single-sex spaces”. As a result of this furor, the lives of transgender people have become the subject of open debate. Trans people now see their legitimacy questioned, and their ability to access services increasingly being placed under the microscope. This article argues that the literature on radicalization – developed in response to domestic terrorism – can explain these developments. UK lobby groups are successfully pushing a radical agenda to deny the basic rights of trans people, and are doing so under the cover of “free speech” – a sacrosanct element of life in Anglo-Saxon countries.