Shayler
Threats of very serious psychological harm may suffice.
Hudson and Taylor
The threat must be of death or serious injury.
Rodger and Rose
The threat must be external to D
Valderrama-Vega
The cumulative effect of all the threats, not all of which need involve death of serious injury, may be considered by the jury.
Howe
If the threat is to persons other than D, they must be people for whom D “reasonably regards himself as being responsible” and it has to “at least be possible to describe the individuals by reference to the threat.
Cole
The threat must be directed at the offence committed (may be overruled by Martin (David)).
Graham (2 precedents)
Bowen (3 precedents)
Hasan (2 precedents)
David and Pittaway
The threat must not have expired when the offence was committed.
Howe/Gotts
Duress is not a defence to murder/attempted murder.