Employment and labour market regulation initially appeared as one of the solid red lines in the UK’s renegotiation of the country’s place in the EU. The basic argument is that the UK’s more deregulated labour market would sit uneasily in the more organised models, based on statutory instruments or collective bargaining, found on the continent. While there is a legitimate problem here, EU employment regulations appear manageable from the point of view of business, while unions see them as important tools for socially responsible economic restructuring. Most of UK employment case law is now deeply entangled with EU law; labour market regulations have, on the whole, become part of the way of doing business in the Single Market; and a simple cost–benefit analysis appears impossible because some costs are not quantifiable and the costs of others are reduced when taken as a bundle. Labour unions agree that transposition of European law needs to be done taking into account local sensitivities, while internationally oriented companies do not see EU regulations on the whole as detrimental to business. Importantly, though, the costs and benefits of EU employment regulations are not symmetrically distributed across different companies: large companies are better able to reap the rewards and accommodate the costs of operating in the Single Market than smaller companies.