Final answer:
The leading British critics of King George's policies were primarily the American colonists themselves. They viewed King George III's actions as tyrannical and were influenced by the political thought of philosophers like John Locke.
Step-by-step explanation:
The leading British critics of King George's policies were primarily the American colonists themselves. They criticized King George III's use of absolute authority and viewed his actions as tyrannical. The colonists were influenced by the political thought of philosophers like John Locke, who emphasized the role of government in protecting life, liberty, and property. The colonists' reactions to King George's policies ultimately led to the American Revolution and the establishment of an independent United States.