[DiogenesKynikos]

> they effectively have a one use “sorry, but they’ve gone too far, I’m dismissing this government” card they can play

In reality, they don't have that card. The day the monarch tries to dismiss an elected government will be the day the monarchy is abolished and the UK becomes a republic.

[karencarits]

During the invasion of Norway in WWII, the King was requested by the Germans to appoint a new nazi-friendly prime minister, which the King refused. But as you have pointed out, what the King actually did was to say to the sitting government that he would abdicate if the government gave in to the threats of the Germans. Later during the war, when the King was in exile in England, some parts of the parliament left in Norway (the nazi-friendly part) required the King to abdicate, which he refused.

These episodes are known as "the King's no" and were very important symbols for the resistance movement in Norway (https://snl-no.translate.goog/Kongens_nei?_x_tr_sl=no&_x_tr_...). The actual importance of these "nos" are controversial, but they carry a significant symbolic value and made it harder for the Germans to establish a new government with any legitimacy. I guess faking a vote would have been rather easy, trying to change King much harder