Final answer:
The judicial branch is responsible for determining whether legislation is permissible by interpreting laws and assessing their constitutionality in a democratic system with a separation of powers.
Step-by-step explanation:
Who determines whether legislation is permissible? The entity responsible for this in a democratic system with a separation of powers is typically the judicial branch. The judicial branch, which consists of courts and is headed by the Supreme Court in some countries like the United States, has the authority to interpret the laws and decide on their constitutionality. This means that they can review laws passed by the legislative body and determine if they align with the country's constitution, thereby making a ruling on whether the legislation is permissible or not.
In Canada, similar to other democratic nations with a separation of powers, it is the judicial branch, and not the Parliament of Canada, the prime minister, or the federal government that has the final say on the permissibility of legislation. It's important to note that while cabinets may craft legislation and the prime minister leads the executive branch, the judicial branch remains the ultimate interpreter of laws.