http://www.ukba.homeoffice.gov.uk/sitec ... iew=Binary
MIGRANTS WORKING ON A CONTRACT BASIS
Where a migrant is working on a contract basis and has been supplied to you by another
445. organisation, you must be the organisation which has full responsibility for determining the duties, functions and outcomes, or outputs of the job the migrant is doing.
446. An example of this would be where Company A has a contract with Company Z to deliver a piece of work. A migrant who is sponsored by Company A, may be sent to work for the duration of the contract with Company Z, but they remain employed by Company A throughout the period of the contract and Company A is fully responsible for deciding the migrant’s duties, functions, outputs or outcomes. In this example, Company A remains as the migrant’s sponsor.