From Mental Health Law Online
The donor made an EPA appointing A and B to act jointly. He then added: "so long as neither Attorney dies or is incapacitated in which eventuality the other Attorney is empowered to act on his own". On the application of the attorneys the court severed the restriction as being incompatible with a joint appointment. [OPG summary - EPA case.]
Summary from OPG website.
Title: Re Berg (an order of the Senior Judge made on 31 December 2010)
Heading: Severance of restrictions incompatible with a joint appointment
Not on Bailii - no transcript