Under what two circumstances will there be a by-election in an MP's constituency?

Okay, let's talk about by-elections. In the UK, we elect Members of Parliament, or MPs, to represent specific areas called constituencies. These MPs usually serve for a fixed term, typically five years, until the next general election. However, sometimes an MP can't complete their term. The two main reasons for this are death or resignation. Think of it like this: if an MP passes away, they obviously can't continue representing their constituency. Similarly, an MP might choose to resign for various personal or political reasons. When either of these things happens, we need to elect a new MP to fill the vacant seat. This is where a by-election comes in. It's a special election held outside of the regular general election cycle, specifically to choose a replacement MP for that constituency. While an MP might get ill or travel abroad, these situations don't create a permanent vacancy. The seat remains theirs, and they can still perform their duties, even remotely. Only death or resignation triggers the need for a by-election to ensure the constituency has proper representation in Parliament.