Inchoate liability

Attempts

Anderton v Ryan [1985] AC 560
R v Shivpuri [1987] AC 1

Conspiracy
Shaw v DPP [1962] AC 220
Scott v Commissioner of Police [1975] AC 819

Incitement
Whitehouse [1977] 2 WLR 925
DPP v Armstrong  [2000] Crim LR 379 QB
Applin v Race Relations Board [1975] AC 259
Fitzmaurice [1983] QB 1083

Further reading
Law commission Report  - Inchoate liabilty for assisting and encouraging crime