European citizens are largely unfavourable to immigration. These restrictive attitudes are linked to such factors as the unemployment rate and risk of poverty, as well as to competition for employment and welfare resources. Refuting insider/outsider theories, this article shows, via an analysis of recent European Social Surveys, that national social protection policies can reduce hostility towards immigration, insofar as they moderate social inequality and the risk of poverty. Ethnic and racial differences are problematic for the ‘egalitarian compromise’ underpinning the welfare state. Nonetheless, strong trade unions and social protection policies are associated with greater integration of immigrants. Over time, the future sustainability of welfare systems may depend on the participation of immigrants as a political force, making their integration even more important.