The UK government is presented with a unique opportunity to lead in the development of responsible, high-value AI by establishing a cross-economy AI Growth Lab that addresses the challenges of data access, regulatory fragmentation, and organisational hesitation. The proposal emphasizes the need for centralized coordination across regulators to provide clear guidance and reduce legal risks, as well as the importance of focusing on commercially relevant and scalable AI applications that rely on cross-sector datasets. By embedding privacy-enhancing technologies and secure infrastructure within the Lab, it aims to facilitate real-world testing without compromising data security. The success of this initiative depends on transparent governance, real-time monitoring, and central government ownership to ensure consistent regulatory guidance across various sectors, ultimately setting a global standard for deploying AI responsibly on sensitive data.