A labour provider is a person or company who supplies workers to a third party. This includes employment agencies, employment businesses and gangmasters. A gangmaster is someone who supplies a worker to another person to do work to which the Gangmasters (Licensing) Act 2004 applies.f you are a labour user you should: 1  Carry out a risk assessment of the tasks the worker will be expected to undertake; 2  Ensure the control measures identified in the assessment are effective, are in place and are maintained; 3  Pass relevant information on to your labour provider(s).