Final answer:
The English Constitution tradition that now has the force of law due to long-standing practice is known as Common Law, which evolves through judicial decisions and precedents rather than through legislative statutes or amendments. The correct option is 3.
Step-by-step explanation:
The portion of the English Constitution that can be described as a "tradition that has been in practice so long it now has the force of law" is best exemplified by Common Law. Common Law is a system where law is developed through the decisions of courts, with judges creating rules that stand as precedents for future cases.
This system is rooted in the history and traditions of English law, and it emphasizes the importance of past court rulings in shaping the legal landscape. Essentially, these traditions become so embedded within the legal framework that they acquire the status and enforceability of law without needing to be written into statute.
In contrast to legislative acts or codified amendments, common law evolves through the interpretation and application of legal principles by judges in various cases over time. It stands as a critical component of the British legal system, influencing not only UK jurisprudence but also that of countries that have adopted the common law tradition, such as the United States.