Final answer:
Roman and Greek representative government has most directly impacted the British form of government.
Step-by-step explanation:
The form of government that has most directly impacted the British form of government is Roman and Greek representative government.
During the Roman Republic and the Athenian democracy in ancient Greece, the concepts of representative government and direct democracy were developed. These ideas later influenced the development of the British form of government.
In the Roman Republic, citizens elected representatives to make decisions on their behalf, while in ancient Athens, citizens directly participated in the decision-making process. These forms of government laid the foundation for the democratic principles and representative institutions that are central to the British political system.