Système politique britannique : Bagehot et Constitution

Analyze the British political system by contrasting the 'dignified' and 'efficient' parts of the constitution as defined by Walter Bagehot. Discuss how the Monarch, while technically holding the 'Royal Prerogative', operates under strict constitutional conventions. Specifically, evaluate why the Sovereign’s political neutrality is essential for the system's stability, and explain the legal mechanism by which the Executive branch—the Prime Minister and the Cabinet—now exercises powers once held by the Crown. Your response should address the limitation of powers after the $1911$ and $1949$ Parliament Acts.