According to the Interlaken principles, relations with third countries should not slow down the process of integration; compromise the EU’s decision-making autonomy; or share power with non-members. Access to the benefits of the EU Internal Market is conditional, with partner states expected to assume key elements of the acquis communautaire. In practice, there is not a linear relationship. The EU prefers structured, institutionalised arrangements conforming to existing models and encompassing all aspects of the relationship. Yet the existing models themselves, including those in Michel Barnier’s ‘ladder’ are themselves the product of ad hoc deals and often far from comprehensive.