You must be the only person who regards Francis Bell as "my guy", but as far as I'm aware he was really only an Interim Prime Minister, so I've excluded him as well as Hugh Watt and William Hall-Jones.
All of those men were Acting Prime Minister after their predecessors died, but made it clear they intended to step down once their Parties elected a replacement.
All of those men were Acting Prime Minister after their predecessors died, but made it clear they intended to step down once their Parties elected a replacement.