Article 140 lets the Supreme Court give itself new powers whenever it wants.

Article 140 requires Parliament to pass a law; the Supreme Court cannot use this Article to grant itself powers on its own.

Article 140 and Article 142 are the same thing.

Article 142 gives the Supreme Court its own inherent power to do complete justice in a case; Article 140 is about Parliament creating supplemental powers by legislation, which is a different mechanism.

The Constitution of India

Article 140

Ancillary powers of Supreme Court

Parliament may by law make provision for conferring upon the Supreme Court such supplemental powers not inconsistent with any of the provisions of this Constitution as may appear to be necessary or desirable for the purpose of enabling the Court more effectively to exercise the jurisdiction conferred upon it by or under this Constitution.§

Why this exists

The Constitution gives the Supreme Court specific powers and jurisdiction in various Articles (like 32, 132-136, 141, 142). The framers realized that as the Court functions in practice, it might need extra procedural or supplemental tools not explicitly spelled out elsewhere, to make its existing powers work smoothly. Rather than list every possible power in the Constitution itself, Article 140 lets Parliament fill such gaps through ordinary legislation, subject to the safeguard that any such law cannot contradict the Constitution.

How courts read it

There is little independent case law interpreting Article 140 on its own, since Parliament has rarely invoked it directly. Courts have, however, been careful to distinguish it from Article 142, which gives the Supreme Court itself an inherent power to pass orders necessary for 'complete justice'—a power flowing from the Constitution directly, not from any Parliamentary law. Article 140, by contrast, depends on Parliament actually enacting a law; it does not by itself create any power for the Court.

Common misconceptions

Myth: Article 140 lets the Supreme Court give itself new powers whenever it wants.
Fact: Article 140 requires Parliament to pass a law; the Supreme Court cannot use this Article to grant itself powers on its own.
Myth: Article 140 and Article 142 are the same thing.
Fact: Article 142 gives the Supreme Court its own inherent power to do complete justice in a case; Article 140 is about Parliament creating supplemental powers by legislation, which is a different mechanism.