Who is Keir Starmer, the self-described socialist set to lead the U.K.? Some Brits still don't...

A man on the verge of ruling this key American ally, the world’s sixth-largest economy, there is little consensus about what kind of leader Starmer, 61, will become or even what kind of man he is.

He has the most blue-collar upbringing of any candidate in a generation while at the same time being the first since the 1950s to already have the title “Sir” after having been knighted by the monarchy. He is a vegetarian and a self-described socialist but also a hate figure for many leftists who accuse him of veering rightward in search of power. And while friends describe him as an affable but hypercompetitive soccer fanatic, in public he often appears stiff and lacking charisma.