Does the King have to swear in the new Prime Minister, and can Charles III call a General Election?

As Sir Keir Starmer makes his Downing Street exit and Andy Burnham heads to Buckingham Palace, Britain witnesses its seventh Prime Minister in a decade take charge. While political handovers at No10 move fast, centuries of constitutional tradition lie behind the palace doors. From private audiences with King Charles III to official royal proclamations, the...