Simplify the following text for a Grade 12 native English-speaking person.
Original: The Leader of Her Majesty 's Most Loyal Opposition in the United Kingdom ( more commonly known as the Leader of the Opposition in the House of Commons ) is the politician who leads the Official Opposition ( Her Majesty 's Most Loyal Opposition ) in the United Kingdom .
Simplified: The Leader of the Opposition ( sometimes known as the Leader of the Opposition in the House of Commons ) in the United Kingdom is the politician who leads Her Majesty 's Loyal Opposition .