The information for this article comes from official statistical data, official reports, secondary literature and interviews with privileged observers in each country. In line with aspects of action research agenda was elaborated in a workshop with representatives of unions, employer associations and migrant associations, held in Barcelona in February 2010. Thirteen in – depth, semi-structured interviews were conducted during 2010 with representatives of all the main parties involved in each country : unions, employers, migrant organizations and health and safety authorities . Seven interviews were carried out in the UK and five in Spain. In addition, an interview was carried out with the construction trade union Budowlani in Poland, as a sending country.