G.R. No. 185066 - Philippine Charter Insurance Corp. vs. Philippine National Construction Corp.

Petitioners include the League of Cities of the Philippines (LCP) represented by its National President Jerry P. Treaas, and several cities such as Iloilo and Calbayog, as well as Treaas in his personal capacity as taxpayer.
Respondents are the Commission on Elections (COMELEC) and 16 municipalities—Baybay, Bogo, Catbalogan, Tandag, Borongan, Tayabas, Lamitan, Tabuk, Bayugan, Batac, Mati, Guihulngan, Cabadbaran, Carcar, El Salvador, and others—that sought cityhood under various Cityhood Laws.
Numerous cities intervened to oppose the cityhood of these municipalities, fearing reduced Internal Revenue Allotment (IRA) shares.

On November 18, 2008, the Supreme Court en banc struck down 16 Cityhood Laws for violating Section 10, Article X of the 1987 Constitution and the equal protection clause.
Respondents moved for reconsideration twice; the Court denied the first motion on March 31, 2009, and by a 6-6 tie vote, denied the second motion on April 28, 2009.
The 18 November 2008 Decision thus became final and executory, recorded officially on May 21, 2009.
On December 21, 2009, the Court en banc reversed the earlier decision and upheld the constitutionality of the Cityhood Laws.
Petitioners then filed ad cautelam motions for reconsideration and a motion to annul the December 21, 2009 Decision.
The present resolution reinstates the November 18, 2008 Decision, declaring the Cityhood Laws unconstitutional.

Section 10, Article X of the 1987 Constitution: prohibits creation of local government units except in accordance with criteria in the Local Government Code and subject to plebiscite approval.
Republic Act No. 7160 (Local Government Code of 1991), particularly Section 450, sets criteria for city creation.
Republic Act No. 9009 amended Section 450 to increase the minimum income requirement from Php 20 million to Php 100 million.

Whether the Cityhood Laws granting exemptions to the increased income requirement under RA 9009 violate Section 10, Article X of the Constitution.

Whether the exemption provision in the Cityhood Laws violates the equal protection clause for giving preferential treatment based on the timing of filing cityhood bills.

The proper application of the operative fact doctrine in relation to the implementation and declared unconstitutionality of the Cityhood Laws.

The effect of a tie vote on motions for reconsideration concerning the constitutionality of laws under the Rules of Court and Supreme Court precedents.

The jurisdiction of the Supreme Court to reconsider or annul its prior final and executory decisions.