This paper uses the 2010 Ethnic Minority British Election Study to look at the political attitudes of Muslims in Britain. It tests the relationship between political alienation and political participation on the one hand, and Islamophobia and disapproval of British military involvement in Afghanistan on the other. The principal findings are that perceptions of Islamophobia are linked to greater political alienation, to a greater likelihood of non-electoral participation and to a lower likelihood of voting among Muslims. Likewise, disapproval of the war in Afghanistan is associated with greater political alienation and a greater likelihood of some types of non-electoral participation. There is strong evidence that British Muslims are more likely to interpret discrimination they experience as motivated by their religion and that they perceive more prejudice at the group level. These findings have two theoretical implications. First, they support the theory that non-electoral participation is motivated by dissatisfaction with the party political system. Second, they suggest that perceptions of sociotropic discrimination (for minorities) and a rare salient political issue in which all parties are in opposition to most voters can lead to negative affect towards the political system and stimulate non-electoral participation at the expense of voting.