From The Grammarly Blog:
If you want to voice your agreement with someone during a debate (especially if you’re a member of the UK Parliament), you will shout “hear, hear.” But as long as you’re shouting, no one will notice you’re wrong if you shout “here, here” because the words are pronounced the same.
The United Kingdom has a long and proud history of parliamentarism. The current incarnation of the country’s Parliament, the Parliament of the United Kingdom, has a history that can be traced through its predecessors, the Parliament of Great Britain and the Parliament of England, all the way to the early thirteenth century. As is often the case with places and institutions that have a long tradition, we can find relics of the past that persist in modern times. For instance, MPs are still offered snuff before they enter the Chamber. There is still some use of Norman French in the legislative process. And MPs still shout “hear, hear” when they agree with something one of them has said.
Link to the rest at The Grammarly Blog