This is the crux. Like stereotypes, conspiracy theories have to contain a kernel of truth in order to function. The ruling class do conspire, but it’s not through the Bilderberg Group, The Elders of Zion, the Freemasons (well, maybe a little) or the Illuminati, it’s the Bank of England, the CBI, the G8, the EU Commission and other unelected bodies.
Of course Parliament has a limited executive and legislative authority, but the real levers of power reside in remote and unelected bodies. Although I shed no tears, witness how the Bank of England and other bodies effectively removed a British Prime Minister in a matter of weeks when she overstepped the mark.