Despite the inference that there could be multiple options, being a third country is a binary opposite of a member state in European parlance. The possible source of ambiguity in this distinction is that there are two implied alternatives to being a third country. Between themselves, EU member states use the term third country to refer to countries which are not EU members, in much the same way a verb might be conjugated. To complete the analogy, the first person is the member state speaking, the second person refers to the other member states on an equal footing, while the third person is identified as a separate, external non-member.
Unlike other areas of European policymaking, in which a wide spectrum of buying-in is accepted without argument, the distinction between being a member state and a third country is fundamentally indivisible. The UK negotiators failed to gain any traction in their attempts to carve out a halfway quasi-membership status that might have opened the way to feathering a cuckoo’s nest of a la carte patronage for British interests. The choice of Michel Barnier to lead Brexit talks for the European Union reflected his commitment to the indivisible membership of a European community that was used to accommodating consensus policymaking in specific areas and contexts.