The UK does not vote for prime ministers; none are elected. Voting regions vote for MPs, and MPs collectively choose their leader. A large part of why the last

The UK does not vote for prime ministers; none are elected. Voting regions vote for MPs, and MPs collectively choose their leader. A large part of why the last leaders of both major parties have been populists, out of keeping with UK history, is because parties let their own private memberships play significant roles in choosing their leader -- this has handed the choice of PM from directly elected MPs to profoundly unelected party members. The only reason the current PM is sane is because the ruling party decided to ignore the members this time, having seen how basically incompetent their members have become.