Estimates of the number of migrant workers on the site - mostly from Poland and Baltic states within the European Union - range from 10 to 70 per cent. According to the Olympic Delivery Authority's last month employment figures for the Olympic Park, 58 per cent of the 2,700 workforce were resident in London and 24 per cent from the East End. However, the figures do not indicate the worker's nationality - or how long they have lived in Britain.