This blog examines the ever-growing catalogue of restrictions on who can participate in the EU public procurement market and, consequently, with whom the public buyer (the contracting authority) cannot contract. We start by showcasing how freedom of contracting – one of the fundamental principles of contract law – is limited in the context of public procurement (section 1). Next, we look outside of EU Public Procurement Directives to sources of additional restrictions. These represent a clear reaction to contemporary challenges and include Sanctions Against Russia (section 2), Foreign Subsidies Regulation and International Procurement Instrument (section 3), Deforestation-Free Products Regulation and the Proposal for an Anti-Greenwashing Directive (section 4). Finally, we provide some conclusions.