It's not really like that. The PM is essentially a monarch. But like all British monarchs they rule with the consent of their Barons - these days the MPs in th

It's not really like that. The PM is essentially a monarch. But like all British monarchs they rule with the consent of their Barons - these days the MPs in their party that will give them a majority in the House of Commons. The PM has a great deal of power, but their grip on power is precarious as we saw with Boris. They are really just first amongst equals. If they don't deliver they are out and another of the elected MPs will take charge. Really it is the MPs that select their leader. However in the Tory case if they can't reach a consensus they refer it to their party for a tie breaker. Remember the UK has a Parliamentary system, not a presidential system. There is no separation of powers in the UK. Everybody that matters sits in the House of Commons as an elected Member of Parliament, and the government is drawn from that set of people - with a permanent civil service providing the supporting functions.