The publication of the new rule book on undercover policing is welcome, but it fails to spell out clear criteria concerning whether an operation is needed in the first place. Unlike the vast majority of undercover operations, the Special Demonstration Squad had a general remit of gathering intelligence on campaigners, trade unionists, and politicians. There was no specific link to a police investigation nor an alleged crime and that is where the problems started. The rule book should require senior officers to spell out the purpose of the operation, how it links to a specific investigation and why the information cannot be gathered by other means.

A further problem is that sleeping with a target is still not illegal, as it is in other countries. We need a law so that officers who break the rules and cause distress and disruption to the lives of innocent people can also be prosecuted