The mysterious notes passed urgently between MPs in the Commons on Sept 8 offered the first public indication that something was amiss.
Liz Truss, the Prime Minister, had just delivered an energy statement containing the single biggest economic intervention in British peacetime – but front-bench MPs appeared distracted, whispering to each other with concerned looks.
Sir Keir Starmer, the Labour leader, was delivering his response when Nadhim Zahawi, the Chancellor of the Duchy of Lancaster, entered the chamber and squeezed between Ms Truss and Kwasi Kwarteng, the Chancellor.
He whispered into the Prime Minister’s ear before handing her a note folded into a square. A similar note was passed to Angela Rayner, Sir Keir’s deputy.
Shortly afterwards, at 12.20pm, Buckingham Palace announced that the Queen was unwell and doctors were concerned for her health. Senior members of the Royal family were dashing to her side. Her Majesty died a few hours later.
Ms Rayner has now revealed the contents of the note she passed to Sir Keir and the dilemma she faced as she contemplated how to interrupt him in view of the television cameras.
She told the News Agents podcast, presented by Emily Maitlis and Jon Sopel, that the note, written in “plain English”, said: “The Queen is unwell and Keir needs to leave the chamber as soon as possible to be briefed.”
Describing the moment she first realised the monarch’s death was imminent, she said: “I read between the lines on that, because you don’t get a note saying the Queen is unwell if she’s got a bit of a cough or a cold.”
Ms Rayner said “the gravity” of the situation was underlined by the fact that they were prepared to interrupt such a big moment in Parliament.
“I was trying to get the note to him [Sir Keir] without being too dramatic, but also not knowing exactly what was going on, but I needed to get him out of the chamber,” she added.
“I kept the note and I was trying to think, how am I going to get it to Keir without totally ruining what he’s trying to say, because if someone is trying to give you information when you’re in the middle of speaking it’s the most distracting thing, so I was waiting for the opportunity to do it.”
When Ms Rayner looked over and caught the eye of Sir Lindsay Hoyle, the Commons Speaker, he indicated that she needed to get on with it. “He’s giving me the nod of ‘this is actually quite urgent’,” she said. “So I kind of knew that it was quite an important moment.”
Ms Rayner said she was also concerned about how and when the news of the Queen’s death might emerge and did not want that to happen before Sir Keir had been briefed.
“If Keir was at full throttle when the news broke, then I haven’t protected him from the circumstances,” she added. She said she recognised that events were “going to change everything”.
After leaving the chamber, Ms Rayner and Sir Keir were briefed by Simon Case, the Cabinet Secretary, and learned of the monarch’s death shortly before it was announced that evening at 6.30pm.