DPAs were introduced in Schedule 17 of the Crime and Courts Act 2013. The Schedule contains a requirement that the DPP and the Director of the SFO jointly issue a Code giving guidance for prosecutors on a number of matters, including the general principles to be applied in determining whether a DPA is likely to be appropriate in a given case.
A draft Code was published at the end of June and a consultation process, inviting comments from interested individuals and organisations, is currently under way.
via DEFERRED PROSECUTION AGREEMENTS PROSECUTION GUIDANCE — Bribery Library Blog