An outright majority for a Corbyn-led Labour government is unlikely, but not impossible. We have learnt in recent years than almost anything is possible. If it were to transpire, the impact on the British economy could be severely negative — because markets would probably react vigorously and immediately, selling sterling and sterlingdenominated assets of all kinds. Mr Corbyn’s party has emphatically distanced itself from the only Labour government in recent years with a reputation for economic competence: as a result,...