Where is sovereignty held in the UK and US governments, and why does this differ?

Sovereignty is defined as the supreme source of power in a government system. Sovereignty in the UK government is held by Parliament, consequently being named Parliamentary sovereignty. This means that Parliament are the supreme source of power in the UK system of government. This arises from the UK's uncodified constitution, meaning that Parliament has the power to create and alter legislation based on its power granted to it by the electorate. Therefore, Parliament have the power to make legislative decisions that cannot be altered by the Supreme Court, and nor can the executive make legislative decisions without Parliament's consent.Contrastingly, sovereignty in the US is held in its codified constitution. This means that all power resides here, and all legislative decisions must be based on current acts within the constitution, or must create new acts within the Constitution. Based on this, the Supreme Court has the power to strike down Congress' legislation, as their job is to interpret the Constitution. Gun control, a current key issue of political debate in the US, proved difficult for Obama to control due to the lengthy and difficult amendment process created by the need for the Constitution to be amended, needing a 2/3 majority in the chambers and a ¾ majority in state legislatures, rather than just a pass of legislation in the UK Parliament by a simple majority. Therefore, sovereignty in the US and UK governments have different sources due to their different political cultures and systems, allowing for different processes to arise in consequence.