Which writ issued by a High Court or the Supreme Court of India restrains a person from holding a public office to which he or she is not legally entitled?

Introduction / Context:
The Constitution of India empowers the Supreme Court and High Courts to issue writs for the enforcement of Fundamental Rights and for other purposes. These writs, borrowed from English law, include habeas corpus, mandamus, certiorari, prohibition and quo warranto. Each writ has a specific function. This question focuses on the writ used to challenge the legal authority of a person to hold a public office, thereby ensuring that public posts are occupied only by those legally qualified to do so.

Given Data / Assumptions:

• The question is about writ jurisdiction of the Supreme Court and High Courts in India.
• It asks specifically which writ is used to restrain a person from holding a public office they are not entitled to.
• The options given are Certiorari, Mandamus, Prohibition and Quo Warranto.
• We assume basic familiarity with the names and purposes of the five main writs.

Concept / Approach:
The writ of quo warranto literally means “by what authority.” It is used to question the legal authority of a person to hold a public office that is substantive and created by statute or the Constitution. If the court finds that the person does not meet the required qualifications or that their appointment violates legal provisions, it can restrain that person from continuing in that office. Other writs serve different purposes: certiorari quashes judicial or quasi judicial orders, mandamus commands the performance of a public duty, and prohibition prevents lower courts from exceeding their jurisdiction. Therefore, quo warranto is the correct writ in the context of challenging someone's right to office.

Step-by-Step Solution:
Step 1: Recall the meanings of common writs: mandamus (we command), certiorari (to be certified), prohibition (to forbid), and quo warranto (by what authority).Step 2: Identify which writ's purpose is to examine whether a person is legally entitled to hold a particular public office.Step 3: Recognise that quo warranto is designed to challenge the holder of a public office when there is doubt about their legal right to occupy it.Step 4: Note that if the court upholds the challenge, it can order that the person be ousted, restraining them from acting in that capacity.Step 5: Conclude that among the options, the writ of quo warranto is the one that restrains a person from holding an office to which they are not legally entitled.

Verification / Alternative check:
Polity textbooks consistently define writ of quo warranto as one that enables the court to determine the legality of a claim by a person to a public office. They also emphasise that it can be filed by any member of the public, not necessarily the directly affected party, because it concerns the public's interest in lawful occupancy of public offices. Descriptions of other writs do not include this feature of questioning the authority to hold office, which confirms that quo warranto is the uniquely appropriate writ for this purpose.

Why Other Options Are Wrong:

• Certiorari: This writ is used to quash the order or decision of a lower court or tribunal on grounds such as lack of jurisdiction or error of law, not to challenge someone's right to office.
• Mandamus: It commands a public authority to perform a legal duty, but does not directly question the authority of a person to hold a public post.
• Prohibition: It prevents lower courts or tribunals from proceeding in a matter beyond their jurisdiction; it does not deal with the eligibility of office holders.

Common Pitfalls:
Students often confuse certiorari and prohibition because both relate to judicial or quasi judicial authorities. Some also mix up mandamus and quo warranto, as both involve public offices and duties. A simple memory aid is to link quo warranto with the question "by what authority are you sitting in this office?" If the issue is about the legality of the appointment itself, think quo warranto; if it is about compelling action, think mandamus; and if it is about correcting or stopping judicial proceedings, think certiorari or prohibition.

Final Answer:
The writ that restrains a person from holding a public office to which they are not legally entitled is Quo Warranto.