As per case facts, the State of West Bengal filed an Original Suit against the Union of India, challenging the continued registration and investigation of cases by the CBI within ... its territory after the State withdrew its consent under Section 6 of the DSPE Act. The plaintiff argued that such actions were unconstitutional, violated federalism, and usurped the State police's statutory jurisdiction. The defendant, Union of India, raised preliminary objections questioning the suit's maintainability under Article 131, arguing that the CBI is an independent agency not directly controlled by the Union for such matters, that similar issues were pending in other courts, and that the plaint lacked a clear cause of action or suppressed material facts. The question arose whether the suit filed by the State of West Bengal challenging the CBI's actions after withdrawal of consent was maintainable under Article 131 of the Constitution, especially considering objections regarding party involvement, pending appeals, and the Union of India's control over CBI. Finally, the Supreme Court rejected the preliminary objections raised by the Union of India, holding that the State's legal right of immunity from the Union Government's power, arising from the constitutional scheme and federalism, constituted a valid dispute under Article 131. The Court clarified that Article 131's jurisdiction is special and subject only to other specific constitutional provisions like Article 262, not general remedies or pending appeals under Articles 136 or 226, and found that the CBI is an organ established and superintended by the Government of India, making the Union of India a proper party. The Court also found that the plaint disclosed a cause of action and did not involve material suppression of facts, thus the suit was maintainable for proceeding on its merits.