| 1. Cabinet Office - Intelligence and Security Committee |
| Offers news, list of committee members, and links to annual reports and other official publications. |
| http://www.cabinetoffice.gov.uk/intelligence/ |
| 2. Centre for the Protection of National Infrastructure (CPNI) |
| Government authority that provides protective security advice to businesses and organisations across the national infrastructure. |
| http://www.cpni.gov.uk/ |
| 3. GCHQ |
| Official site of the UK Government Communications Headquarters which is the centre for Her Majesty's Government's Signal Intelligence (SIGINT) activities. Includes details of current job vacancies and an online quiz for potential applicants. |
| http://www.gchq.gov.uk/ |
| 4. Investigatory Powers Tribunal (IPT) |
| Official independent tribunal investigating complaints against the Intelligence Services, Police and public authorities relating to interception, surveillance and other conduct. |
| http://www.ipt-uk.com |
| 5. MI5 The Security Service |
| Provides information on the current major threats to UK security and expert security advice designed to help businesses and organisations protect against them. |
| http://www.mi5.gov.uk/ |
| 6. Metropolitan Police Service - Special Branch |
| Provides a brief history and a list of responsibilities, including intelligence-gathering and operations on extremist political and terrorist activity. |
| http://www.met.police.uk/so/special_branch.ht... |
| 7. National Intelligence Machinery |
| Official document explaining how British security and intelligence agencies are organised and funded. |
| http://www.archive.official-documents.co.uk/d... |
