G.R. No. 137000 ; August 9, 2000
CIRILO R. VALLES, petitioner, vs. COMMISSION ON ELECTIONS and ROSALIND YBASCO LOPEZ, respondents.

FACTS

Rosalind Ybasco Lopez was born in Australia in 1934 to a Filipino father and an Australian mother. She settled in the Philippines in 1949 and married a Filipino citizen in 1952. She actively participated in Philippine elections, serving as Provincial Board Member and later as Governor of Davao Oriental. Her citizenship was previously challenged in the 1992 and 1995 elections through petitions for quo warranto and disqualification (EPC No. 92-54 and SPA No. 95-066). The COMELEC dismissed both cases, finding her to be a Filipino citizen by virtue of jus sanguinis through her father and noting the absence of sufficient proof of an express renunciation of her Philippine citizenship.
In the 1998 elections, petitioner Cirilo Valles filed a new disqualification petition (SPA No. 98-336), again contesting Lopez’s citizenship. Valles relied on evidence that Lopez had previously registered as an Australian national with the Bureau of Immigration in 1988, obtained an Alien Certificate of Registration, and held an Australian passport. He argued these acts constituted an express renunciation of her Philippine citizenship. The COMELEC First Division dismissed the petition on July 17, 1998, and its en banc denied reconsideration on January 15, 1999, prompting this petition for certiorari.

ISSUE

Whether the COMELEC committed grave abuse of discretion in dismissing the disqualification petition and ruling that Rosalind Ybasco Lopez is a Filipino citizen qualified to run for Governor.

RULING

The Supreme Court dismissed the petition and affirmed the COMELEC Resolutions. The legal logic is twofold: procedural and substantive. Procedurally, the principle of res judicata, while not strictly binding in citizenship cases per Moy Ya Lim Yao v. Commissioner of Immigration, allows reliance on prior official findings when no new substantial evidence is presented. The COMELEC correctly noted that Valles presented no new evidence beyond what was already examined and ruled upon in the 1992 and 1995 cases, warranting dismissal.
Substantively, on the merits, Lopez is a Filipino citizen. First, she derived Philippine citizenship at birth via jus sanguinis from her Filipino father under the applicable 1935 Constitution. Second, her marriage to a Filipino citizen in 1952 under Section 4 of Commonwealth Act No. 473 (The Revised Naturalization Law) conferred Philippine citizenship upon her by operation of law. Third, her prior acts of registering as an alien and using an Australian passport did not constitute an express renunciation of Philippine citizenship as required by Commonwealth Act No. 63 . Renunciation must be an unequivocal, voluntary act; the use of a foreign passport, while a positive act of renunciation of Philippine citizenship, is not necessarily a renunciation of citizenship if done for reasons of convenience. Moreover, she formally renounced her Australian citizenship in 1992, and her Australian passport was cancelled, which the Court considered. Therefore, the COMELEC did not gravely abuse its discretion in upholding her qualification.