This Working Paper outlines proposals for reforming public procurement law after Brexit. The proposals are set out on the basis that the UK will become a party to the World Trade Organization’s Agreement on Government Procurement (GPA) and that the GPA will also provide the main constraint for regulation. It is proposed, first, that a new hard law regime should regulate not mainly to ensure open markets, as with the current regulations that give effect to EU requirements, but for eight key objectives (to be stated in the legislation a relevant for interpretation), namely: value for money, integrity, accountability, equal treatment, fair treatment of suppliers; effective implementation of industrial, social and environmental objectives; opening markets; and an efficient procurement process. It is then argued that reform should be based on seven principles: an open contracting approach; a single and uniform regime for the Westminster jurisdiction; significant legislative simplification involving a shift from hard to soft law; use of familiar concepts, rules and terminology where appropriate; a rebalancing of interests (away from open market objectives towards value for money, sustainability and reduced procedural costs) and a related shift in regulatory strategy to increase flexibility; a more effective and balanced approach to enforcement; and a common framework across UK jurisdictions. Translating this into concrete reforms, the paper proposes that there should be a single set of regulations to replace the regulations that transpose the EU procurement directives and to cover all other public procurement rules. They should provide a largely unitary regime, removing the distinctions between “regular” public contracts, utilities contracts, defence and security contracts and concessions; and this regime should take as its starting point the approach of the 1990 Utilities Directive (Directive 90/531). Such an approach represents a significant policy shift, offering to a large extent the maximum flexibility afforded by the GPA and also improving the quality of legislation, but in such a way as to preserve benefits of familiarity and certainty.