In May 2023, HM Treasury set out six joint delivery models for cross-government working in Managing Public Money, including details on responsibilities and accountabilities for each model. At one end of the spectrum covered by these models, joint delivery can involve simple collaboration, where departments may collaborate in the development of policy they have an interest in. At the other end, a machinery of government change would be required, with responsibility and funding transfer from one department to another by order of the Prime Minister.9