http://www.gla.gov.uk/media/1584/jrf-forced-labour-in-the-uk.pdf

http://ohrh.law.ox.ac.uk/zero-tolerance-for-severe-forms-of-labour-exploitation-in-the-uk/

note the date below!

http://www.cpc.ac.uk/publications/cpc_working_papers/pdf/2012_WP20_East_Central_European_Migration_Perspective_of_Employers_McCo