A key issue in Britain’s referendum on European Union membership was the free movement of labour into Britain, with Brexit ‘Leavers’ having more negative attitudes towards immigrants compared to ‘Remainers’. Such anti-immigrant attitudes are driven by feelings of threat. As Brexit negotiations continued, the coronavirus pandemic presented a new threat, potentially heightening anti-immigrant attitudes. However, the prominent sacrifices of migrant workers in the fight against coronavirus suggests a potential for softening public attitudes. We ask: how did the COVID-19 pandemic, in the context of ongoing Brexit negotiations, affected anti-immigrant attitudes and how did these effects differ between Leavers and Remainers? Through a survey experiment, we test the effects of priming COVID-19 thoughts, showing that COVID-19 may exacerbate anti-immigrant attitudes among Leavers while having little effect on Remainers. In doing so, we explore the effect of a viral threat on immigration attitudes and heterogeneity in that effect, based on political identities.