Introduction As discussed in Chapter 1, competition law seeks to regulate the market behaviour of businesses, for instance, by prohibiting the abuse of monopoly power and the operation of cartels. Chapter 2 provided a detailed review of the institutions, structures and processes in respect of the public enforcement of both the EU and UK competition law prohibitions (contained in Arts 101 and 102 TFEU and the Competition Act 1998 Chapters 1 and 2 prohibitions respectively). This was a crucial starting point because EU and UK competition law have traditionally been enforced virtually exclusively by administrative bodies: the European Commission and the OFT/CMA. However, the nes imposed by those competition authorities do not compensate directly any of the victims of competition law infringements. The historical primacy of public/administrative enforcement in Europe is in stark contrast with US competition law (‘antitrust law’) where private enforcement plays a more central role. The availability of a well-developed system of class actions has ensured that private enforcement is extremely effective in the US and can result in end-consumers being compensated for their losses. The US system also emphasises the importance of consumer rights, and the possibility of substantial damages awards enhances the deterrent impact of the antitrust laws. Accordingly private enforcement of competition law can: rst, ensure that rights are respected by providing a means of redress for any damage caused by a competition law infringement, either to another business forced out of a market by abusive behaviour or an end-consumer paying excessive prices for a product as a result of a price- xing cartel; and, second, bolster or even replace (where the competition authority has insuf cient resources or does not prioritise sanctions of particular competition law infringements) public enforcement action, in order to enhance or at least ensure the deterrent effect of the competition rules. Accordingly, the European Commission and various Member States, including the UK, have recognised that private enforcement should be encouraged and facilitated.