"These Regulations apply where— (a) an individual ("the worker") personally performs, or is under an obligation personally to perform, services for the purposes of a business carried on by another person ("the client"), (b) the performance of those services by the worker is carried out, not under a contract directly between the client and the worker, but under arrangements involving an intermediary, and (c) the circumstances are such that, had the arrangements taken the form of a contract between the worker and the client, the worker would be regarded for the purposes of Parts I to V of the Contributions and Benefits Act [theSocial Security Contributions and Benefits Act 1992 ] as employed in employed earner's employment by the client." "