G.R. No. 120567 - Philippine Airlines, Inc. vs. National Labor Relations Commission

The 1987 Constitution’s Ordinance apportioned Maguindanao into two legislative districts: the First District comprised Cotabato City and eight municipalities.
Maguindanao became part of ARMM under RA 6734 (as amended by RA 9054); Cotabato City remained outside ARMM (Region XII) after voting against inclusion.

On 28 August 2006, the ARMM Regional Assembly enacted MMA Act 201, creating the Province of Shariff Kabunsuan from eight municipalities of Maguindanao’s First District; it provided for initial provincial officials and declared that “except as may be provided by national law, the existing legislative district…shall remain.”
Three additional municipalities were later carved out, bringing Shariff Kabunsuan to 11 municipalities; Maguindanao was left with its Second District municipalities, while Cotabato City stayed outside ARMM but nominally in the First District.

6 February 2007: Cotabato City’s Sangguniang Panlungsod passed Resolution 3999 seeking COMELEC clarification; 6 March 2007: COMELEC Resolution 07-0407 maintained status quo with Cotabato City in the First District of Maguindanao.
29 March 2007: COMELEC Resolution 7845 reapportioned the First District as Cotabato City alone; 10 May 2007: Resolution 7902 renamed it “Shariff Kabunsuan Province with Cotabato City.”
Petitions filed:

G.R. No. 177597 (Sema) – annulment of Resolution 7902 and exclusion of Cotabato City votes.
G.R. No. 178628 (Marquez) – declaratory relief, prohibition, mandamus, and special election for the First District of Maguindanao with Cotabato City.

Sema: Shariff Kabunsuan is entitled to its own congressional representative by operation of the Constitution; COMELEC acted without jurisdiction and usurped Congress’s exclusive reapportionment power.
COMELEC/OSG: initially challenged procedural remedy but later agreed Section 5(3), Article VI of the Constitution is self-executing, entitling new ARMM provinces to a representative.
Dilangalen: Sema is estopped; Resolution 7902 merely renamed the district; ARMM cannot reapportion (national law only) and Cotabato City lacks the 250,000-population minimum for a lone district.

Are the writs of Certiorari, Prohibition, and Mandamus proper remedies to test the constitutionality of COMELEC Resolution 7902?
Has Dilangalen’s proclamation mooted the case?

Is Section 19, Article VI of RA 9054 unconstitutional in delegating to the ARMM Regional Assembly the power to create provinces, cities, municipalities, and barangays?
If Section 19 is constitutional, is a province created under it entitled to one representative in the House without a national law creating a legislative district?
Is COMELEC Resolution 7902 valid in maintaining the status quo legislative district (“Shariff Kabunsuan Province with Cotabato City”) despite the creation of Shariff Kabunsuan by MMA Act 201?