This article focuses on the responses of British trade unions to the arrival of Polish workers since the 2004 enlargement of the European Union. It is argued that existing definitions and explanations of UK trade union engagement with migrant workers do not capture the strategies that have been used to engage with these migrant workers. We suggest that there have been two sets of responses. First, recruitment and organization activity has centred on inclusion and has been undertaken on new terrains using innovative strategies. Second, we point to the importance of new linkages locally, regionally, nationally and internationally in organizing these new labour market entrants.