When it's a memorandum from the Privy Council Office and enough factors have come into play, making it essential for the Prime Minister to be informed or for recommendations to be made, then it's the national security and intelligence advisor's team that decides to write it.
Someone from the political side of things may on occasion see an intelligence report and ask for more information about it. The notes are prepared by the members of my team, but ultimately, the advisor signs them. As I was saying, the 2017 note was very clear: we were right to be concerned and steps had to be taken with respect to the elections. These mechanisms were implemented.