The Undercover Policing Inquiry (UCPI) covers a period of 50 years, starting with the founding of the Special Demonstration Squad (SDS) in 1968 and continuing to the closure of the National Public Order Intelligence Unit (NPOIU) in 2010.
To facilitate its investigations into each of the undercover deployments, it has divided the work into six Tranches, some of which are chronological in nature and some which are not. There are also other divisions known as Modules.
Each Tranche has its own lead within the UCPI, usually a solicitor who is responsible for overseeing the work specific to it.
The set of questions to be explored by the Inquiry in the different tranches are set out in the Issues Lists which, as well as having general issues, have tranche-specific questions for witnesses.
The five tranches are:
- Tranche 1
: SDS 1968 – 1982, which, due to the impact of Covid-19, was subdivided into
- Phase 1 : Undercover officers 1968 – 1972
- Phase 2 : Undercover officers 1973 – 1982
- Phase 3 : Managers: 1968 – 1982
- Tranche 2 : SDS 1983 – 1992
- Tranche 3 : SDS 1993 – 2007
- Tranche 4 : NPOIU 1999 – 2010
- Tranche 5 : Other undercover policing
- Tranche 6 : management oversight by senior officers, other agencies and government departments
The dates are approximations and some undercovers were moved to adjacent tranches. Tranche 6 is now being run within each of the tranches.
Tranche 1 ran from 2020 to 2022 and an Interim Report was issued in early 2023 .
Tranche 2 was split into two phases to deal with the amount of witnesses providing live evidence, with Phase 1 taking place through July 2024, and Phase 2 due to begin in October 2024.
The remaining tranches will be heard in 2025-2026. The most up-to-date public information on the timescale for the tranches is usually to be found in the annual Inquiry Updates.