Step 1: Understanding the Question:
The question asks us to identify which legal doctrine is referred to as a "fraud on the Constitution."
Step 2: Key Concepts and Approach:
We need to examine the Doctrine of Colourable Legislation.
This doctrine deals with legislative competence and is built on the Latin maxim "quando aliquid prohibetur ex directo, prohibetur et per obliquum" (what cannot be done directly, cannot be done indirectly).
Step 3: Detailed Explanation:
• Colourable Legislation Defined: When a legislature lacks the competence to pass a law on a particular subject, but tries to disguise the law to make it appear within its competence, it is called "colourable legislation."
• Fraud on the Constitution: The Supreme Court has repeatedly held that colourable legislation is a "fraud on the Constitution." It is a covert attempt by the legislature to overstep its constitutional limits.
• K.C. Gajapati Narayan Deo v. State of Orissa (1953): The Court explained that the idea of "colourable legislation" refers to the substance of the act rather than its outward form. The court must look behind the disguise to find the true subject matter.
• Sub-delegation and Excessive Delegation: These are administrative law concepts dealing with the transfer of legislative power to the executive, but they are not defined as a "fraud on the Constitution" in the same way.
Step 4: Final Answer:
Colourable legislation is considered a fraud on the Constitution. Therefore, Option A is the correct answer.