# How does anyone know for sure who the Prime Minister is?

France is famous for tourism, food, and above all, bureaucraty.

When a Prime Minister is heading out, there is a decree saying so. When a new Prime Minister is appointed, a decree is published in the government gazette

It is my understanding that in the UK, the outgoing PM goes to see the Queen or King, tells them they're resigning, and suggests someone to take the office. The monarch invites this person and appoints them as their PM.

Is there anything official, a decree, a publication somewhere, or does the newly appointed PM just go to Westminster, say to everyone there: "The monarch said I'm the boss now!", and everyone just goes with it?

Yes - Sunak and Starmer's meetings with the King are published in the Court Circular, the official listing of the day's Royal events. The entry for July 5th states:

> The Rt Hon Rishi Sunak MP had an audience of The King this morning and tendered his resignation as Prime Minister and First Lord of the Treasury which His Majesty was graciously pleased to accept. Mrs Murty was also received by The King.
> 
> His Majesty received in audience the Rt Hon Sir Keir Starmer MP today and requested him to form a new Administration. The Rt Hon Sir Keir Starmer MP accepted The King’s offer and kissed hands upon his appointment as Prime Minister and First Lord of the Treasury.  
>  Lady Starmer was also received by His Majesty.

The list of business transacted at Privy Council meetings is also published, with the meeting for July 6th including Sir Keir and several of his ministers swearing or affirming their oaths of office:

> This day the Right Honourable Sir Keir Starmer KCB KC (Prime Minister) did, by His Majesty’s command, make solemn affirmation as First Lord of the Treasury.

To add to CDJB's answer:

  * All ministerial appointments are nowadays published on the Government's website; here's the July 2024 page. Initially, the only appointment listed was the new Prime Minister's. The page was updated several times over the next few days as senior ministers, junior ministers and whips were added.
  * In a curious mix of old and new, the PM's appointment was also announced on the Royal Family's official X (formerly Twitter) feed, along with a photo of the King and PM shaking hands.
  * A list of the entire Government appears in Hansard (the official report of everything that happens in the House of Commons), in the edition for the first day of each parliamentary session. Here's the one for 7 November 2023; the list begins on p17, with the PM at the top.



### The King doesn't tell Westminster who is boss, it is the other way round.

The King appointing the PM is a formality - everyone knows who the PM is before it happens. The King is not making a decision, he is rubber stamping a decision that has already been made. In the case of a general election, this decision is made by the public choice picking which party holds a majority and thus which party's leader is now PM. Kier Starmer did not go to the King until the election was (almost) complete and everyone knew that he had a majority in Parliament.

When the PM is changed mid-Parliament, the decision is made by the party choosing its new leader, but again that decision is made before the new leader goes to the King. Thus, when Rishi Sunak became PM his appointment as Party Leader was made before the meeting with the King.

So the new PM isn't coming back from the King and saying to Westminster, "The King says I'm the boss now", the PM is going to the King and saying "Westminster says I'm the boss now".