This thesis focuses on two case studies of 'air transport liberalisation' and tests the effect of 'elite' and 'non-elite' air transport interests on the Proposal making dynamics of the European Commission. The hypotheses test whether the properties of 'liberal intergovernmentalism' (the domination by 'elite interests' at the national level), are reflected in the behaviour of the Commission when formulating its Proposals; this new form of liberal intergovernmentalism is defined as a neo-liberal intergovernmentalism. The hypotheses also test whether an 'elite accommodation' is necessary within interest groups in order for their positions to successfully affect Commission actions. Furthermore, the thesis examines the relevance of the decision making formula within groups, and its subsequent relationship to Commission conduct. The thesis finds that there exist substantial differences in the responses to 'elite interests' within the Commission between DGVII, the transport Directorate and DGIV, the competition Directorate. DGIV is also the unique quasi-judicial arm of the Commission. The thesis finds that a neo-liberal intergovernmentalism indeed exists when one focuses on the role of DGVII, but does not exist when one focuses on the role of DGIV. Furthermore, the thesis finds that the decision making within groups, and their adherence to 'elites within the group' plays a substantial role in determining the position of DGVII, but not in determining the position of DGIV. However, the thesis also finds that the path which DGIV needs to follow in order to pursue its goals, because of its reliance on the College of Commissioners to take 'official' action, is affected by the hypotheses. Crucially however, the thesis also finds that DGIV has an array of options with which to pursue its goals, (if it does not gain the support of a majority of the College), which are considerably beyond what the Member States, and their composite 'elite interests' may be content with.