Final answer:
A potential negative aspect of parliamentary systems is the lack of checks on legislative power, as the executive and legislative branches are combined, often leading to fewer checks and balances.
Step-by-step explanation:
A potential negative aspect of parliamentary systems is the lack of checks on legislative power. In parliamentary systems, the executive and legislative branches are combined, and there's a close relationship between the two, as the prime minister is part of the legislature. This structure makes it challenging for lawmakers to independently oversee or limit the power of the executive, which is a function of the legislative body in a functioning democracy. Unlike presidential systems, where there is a clear separation of powers and mechanisms such as impeachment to check the executive, parliamentary systems often lack these direct checks. Furthermore, the lack of a separate head of state in some parliamentary systems may also conflate the roles, reducing the opportunities for checks and balances. The unicameral nature of some parliaments can exacerbate the issue since there may be no second chamber to provide additional oversight.