BACKGROUND In Ireland, the Public Health (Alcohol) Act represents the first Irish policy attempt to address alcohol harms through an explicitly public health approach. Lauded internationally, the Act aligns with 'best buy' policy recommendations, encompassing a suite of measures targeting the pricing, visibility, advertising and health labelling of alcohol products. Recognising the importance of implementation in the policy process, this study sought to examine the implementation of this multi-component alcohol policy.

METHODS We conducted 15 qualitative interviews with a range of participants with direct knowledge or experience of implementing the Public Health (Alcohol) Act. Participants included policy stakeholders, private sector implementation actors and public health/alcohol policy experts. In the analysis, we used the updated Consolidated Framework for Implementation Research (CFIR) to map barriers and facilitators to implementation of this policy.

RESULTS The study found that barriers and facilitators to implementation were reported for all five domains of CFIR across 21 constructs. Private sector actors placed a greater emphasis on cost-related factors as perceived barriers, whereas policy stakeholders and public health policy experts underlined the reported persistence of industry lobbying as a barrier. All categories of participant perceived a lack of planning for both implementation and policy evaluation, a dearth of resources for inner setting actors and a lack of high-level leadership during policy implementation. Participants also noted the complexity of implementation, lack of relational connections and gaps in innovation design as barriers to implementation. Facilitators included the reported expertise of and relational connections with key individuals, and the policy's alignment with international 'best buy' policy recommendations.

CONCLUSIONS Given the range of challenges perceived in implementing this comprehensive alcohol policy, our study underlines the need for strategic implementation planning, for ongoing evaluation and monitoring of the policy measures, and for adequate resourcing of inner setting actors. The study also notes the importance of anticipating and planning for continued industry lobbying during the implementation phase, acknowledging the reality of the "politics of implementation".