I was given carte blanche. The only kind of constraint around private sector engagement was the history of policing in the U.K., which preserves policing delivery for sworn police officers paid through the public sector. But private sector engagement varies across U.K. police forces. Some have outsourced significant parts of their business, such as call handling and custody arrangements, and others have engaged the private sector differently.
I chose not to go the wholesale outsourcing route, and to engage the private sector through consultancy.