Is europeanisation through conditionality sustainable?: lock-in of institutional change after EU accession

Is the impact of EU accession conditionality sustainable after target states achieve EU membership? Although accession changes the incentive structure for compliance, this article suggests that a lock-in of pre-accession institutional changes can contribute to their persistence even after the EU's sanctioning power weakens. A case study of gender equality institutions in five new member states suggests that a combination of government partisan preferences and veto players explains whether such lock-in occurs. If institutional change no longer fits government preferences, the key condition is the presence of veto players who can lock in institutional change. Rather than impairing Europeanisation, as the literature often assumes, domestic veto players can thus foster it. However, the case study also finds that veto players can lock in non-compliance too if conditionality was unsuccessful, and it appears easier to reverse earlier institutional change than to redress the lack of it.