Counter-extremism measures are an established part of the UK’s counter-terrorism apparatus, with the most significant policy, known as the Prevent Duty, now statutory in public institutions such as nurseries and schools. Counter-extremism policies aim to curb the desires of individuals to become terrorists, primarily through its focus on non-violent ideologies as potential drivers of terrorism. In this talk, I want to explore the idea that whilst counter-extremism measures are designed to limit the possibilities of a terrorist attack, in doing so, they also limit the social and political agency of Muslims. These conditions have created ‘the impossible Muslim’, whose presence in the public sphere is a source of discomfort and tension. I question the possibilities and potential of counter-extremism measures in redefining what a Muslim is and reflect on what it means to exist outside of this proposed model.