I want to know the answer to the following question:
What country's government, on which the US government was modeled, did not formally implement separation of powers?
All the background I'm provided with is that "Under the UK Westminster system, based on parliamentary sovereignty and responsible government, Parliament (consisting of the Sovereign (King-in-Parliament), House of Lords and House of Commons) was the supreme lawmaking authority.". Is that enough to answer the question?
Answer: yes