This was not one case but twenty-five. In C.P.L.A.4818 to 4842/2024, the Chairman WAPDA assailed the Federal Service Tribunal's consolidated judgment dated 29.07.2024 (Appeals No.779 to 803(P)CS/2019), by which the Tribunal had granted proforma promotion and seniority to a batch of employees. WAPDA's argument was structural: newly enacted rules, it said, applied to these employees and defeated their claims — including with retrospective effect.
The Supreme Court — judgment authored by Mr. Justice Muhammad Ali Mazhar, with Ms. Justice Musarrat Hilali and Mr. Justice Irfan Saadat Khan, dated 02.06.2026 — dismissed all twenty-five petitions and refused leave. The Court confirmed two principles as the tagline of the judgment: first, the seniority of employees cannot be affected by the retrospective application of newly enacted rules; second, new rules or amendments detrimental to vested rights shall operate prospectively only. The Court further found no misreading or non-reading of evidence by the Tribunal.
This is now one of the clearest recent statements of the anti-retrospectivity rule in service law. A department cannot rewrite the past with a new rulebook: rights that have vested — seniority earned, promotions accrued — are shielded from later rule changes that would operate backwards. Prospective operation is the default; retrospectivity needs express sanction, and even then it cannot snatch vested rights.
The practical fallout is large because WAPDA is one of the country's biggest employers and the 25-petition batch signals how many employees were affected. For civil servants everywhere, the holding is a shield: agar aap ka haq ban chuka hai, to naya rule usay peechay se nahi cheen sakta. Departments must apply new rules forward — and live with the seniority the old rules created.