11th Congress—The House of Representatives enacts into laws 33 bills converting 33 towns into cities. The Congress, however, does not act on 24 other cityhood bills.

12th Congress—Republic Act 9009 is enacted.  The law increases the minimum income requirement for cityhood from P20 million to P100 million. After the law took effect, the Congress adopts Joint Resolution No. 29, which seeks to exempt the 24 municipalities from the minimum income requirement prescribed by RA 9009. The Senate, however, fails to approve the resolution.                 

13th Congress—The House re-adopts Joint Resolution No. 29 as Joint Resolution No.1 and forwards it to the Senate for approval. The Senate fails to approve it. Congressmen of the 16 municipalities vying for cityhood files 16 cityhood bills that contain provision exempting them from the P100- million income requirements set by the Local Government Code, as amended by RA 9009.

December 22, 2006—The House of Representatives approves the cityhood bills.

February-June 2007—The Senate approves the cityhood bills.

March-July 2007—The cityhood laws lapses into law without the signature of President Gloria Arroyo.

March 27, 2007—The LCP files its first case in the Supreme Court after six towns were converted into cities.

May 4, 2007—Another case is filed by the LCP after six more towns were converted into cities.

June 14, 2007—A third case is filed following the creation of three more cities.

September 28, 2007—A consolidated case is filed after the municipality of Naga in Cebu was converted into a city
 
November 18, 2008—The Supreme Court, voting 6-5, nullifies the conversion of the 16 cities and declared the cityhood laws unconstitutional.

December 10, 2008—The League of 16 cities files a motion for reconsideration.—Research by Jesus F. Llanto, abs-bnNews.com/Newsbreak.

Source: News reports, Supreme Court decision voiding 16 cityhood bills