This book deals with the cartel offence introduced into UK law by the Enterprise Act 2002. It is now, for the first time, a criminal offence to operate certain cartel arrangements in the UK, and those found guilty of the offence face the prospect of fines and/or imprisonment. This presents new challenges for competition lawyers, who may not have expertise in criminal law, and criminal lawyers who are unlikely to have expertise in the complex substantive issues raised by competition law. This book addresses these issues, providing a guide to the workings of the provisions, explanations of the definitions set out in the Act, and an analysis of the relationship of the new offence with the existing UK and EC competition law. Human rights issues and practical considerations in the application of the relevant procedural law are also dealt with. Relevant OFT guidance and statutory provisions are published in the Appendix.