G.R. No. 46267 - Zandueta vs. De la Costa

Francisco Zandueta filed a quo warranto petition to declare Sixto de la Costa illegally occupying the office of Judge, Fifth Branch, Court of First Instance (CFI) of Manila, and to restore Zandueta to that office with costs.
The contested office was Judge of First Instance, Fifth Branch of the CFI of Manila, Fourth Judicial District.

On June 2, 1936, President of the Philippines issued an ad interim appointment for Zandueta as Judge of First Instance, Ninth Judicial District (City of Manila), Fifth Branch; confirmed September 8, 1936.
He discharged judicial duties under this appointment until November 7, 1936.

Commonwealth Act No. 145 (Judicial Reorganization Law) took effect November 7, 1936, creating the Fourth Judicial District (Manila and Palawan). On that date, Zandueta received a new ad interim appointment to that office and took the oath.
After the National Assembly adjourned November 20, 1937 without acting on his appointment, a second ad interim appointment issued November 22, 1937; he took a new oath and performed executive acts over Manila and Palawan (designation of administrative officer, notary appointments, leave authorizations).

On May 19, 1938, the Commission on Appointments disapproved Zandueta’s ad interim appointment; he was notified May 20, 1938.
On August 1, 1938, President appointed Sixto de la Costa as Judge of First Instance, Fourth Judicial District (Fifth Branch, Manila and Palawan); the Commission approved, he took the oath, assumed office, and received a final appointment.

De la Costa admitted some allegations, denied others.
He pleaded estoppel—Zandueta accepted and qualified under Commonwealth Act No. 145, performed judicial and administrative acts, and thus cannot attack the law’s constitutionality or reclaim his former office.

Whether Zandueta, having accepted an appointment to a reorganized and incompatible judgeship and performed its duties, is estopped from (a) challenging the constitutionality of Commonwealth Act No. 145 and (b) reclaiming his prior office.
Whether, upon disapproval of Zandueta’s ad interim appointment, he ipso jure ceased to discharge the functions of Judge, First Instance, Fourth Judicial District, and whether De la Costa lawfully occupies the office.