Contract law is currently undergoing a major transformation as a result of various developments in the economy. The division into different categories, on which Swedish contract law previously rested, no longer applies, such as the division between national and international, between public and private and between goods/services and intangible assets. Within the overall research project, of which this doctoral project is a central part, we seek to analyze and find common principles in today's general contract law based on these three trends. The doctoral project focuses on the public-private dichotomy. The division in contract law between public and private law is today under strong pressure due to privatization, new rules for public procurement, etc. Situations often arise where public and private law rules both overlap and counteract each other. The collision between public and private law is particularly evident in public procurement. With a focus on the contracting authority's civil liability, and in particular on presumptive conflicts between general contract law and the EU Procurement Directive, the purpose of this doctoral project is to clarify whether and if so, how the general doctrines of national contract law on duty of loyalty, pre-contractual liability, etc. are reshaped in the light of EU law's requirements for equal treatment of suppliers and the safeguarding of competition in the market for public contracts.