Is redistricting in the Philippines possible?

And by redistricting, I mean reapportionment as stated in Article VI, Section 5, Paragraph 4:

Within three years following the return of every census, the Congress shall make a reapportionment of legislative districts based on the standards provided in this section.

Just recently, Cavite (and I think Camarines Sur) were reapportioned, although by standards I don't know. Perhaps they followed the "minimum" guideline (in order for any grouping of LGUs to become a district, it must have a population of at least 250,000 and should be composed of a “contiguous, compact, and adjacent territory.”). However, this led into Cavite increasing its districts from three to seven! Now, the province has the most number of Congressmen, and it is also the most populous province.

Cavite is an odd case, however. Cavite leapfrogged everybody to become the most populous province in the country, that's why they were stuck with three districts for much of the operation of the 1987 constitution. Among the provinces (LGUs) that were previously at the top (in order of 2007 population), Bulacan, Quezon City, Pangasinan and Laguna, only Laguna and Quezon City were stuck with 4 congressmen. In fact, Quezon City's 2nd district (most of the northern part of the city) may be the most populous district in the country.

So why not redistrict the entire country? But first we have to set the rules.
First, limit the number of congressmen. Let us peg it at 250 level. Now, the constitution mandates that 20% of Congressmen must be sectoral (party-list) representatives. So 80% of 250 is 200. Now, let's divide the population of the Philippines (88,542,548) with 200. We come up with 442,713 (almost twice as much as the current minimum) rounded to the nearest whole number. Next, we get the population of the provinces, cities not within a province, and every LGU that has a Congressional district on their own, and divide that by 442,713, with the quotient rounded to the nearest whole number. Then, we reset LGUs that have a Congressman by their won which are not provinces back to zero (this affects two cities -- Navotas and San Juan. Provinces are allowed to keep their one representative even if they are below the 250,000-population floor.

The results are (click here if you are too bored to scroll down):

LGU	Type	Population	New	Now	+/-
Cavite	province	2,856,765	6	7	-1
Bulacan	province	2,826,936	5	6
Quezon City	highly-urbanized city	2,679,450	6	4	2
Pangasinan	province	2,495,841	6	6	0
Laguna	province	2,473,530	6	4	2
Cebu	province	2,439,005	6	6	0
Negros Occidental	province	2,370,269	5	6	-1
Rizal	province	2,284,046	5	4	1
Batangas	province	2,245,869	5	4	1
Pampanga	province	1,911,951	4	4	0
Nueva Ecija	province	1,853,853	4	4	0
Iloilo	province	1,691,878	4	5	-1
Manila	highly-urbanized city	1,660,714	4	6	-2
Quezon	province	1,646,510	4	4	0
Camarines Sur	province	1,533,305	3	5	-2
Caloocan	highly-urbanized city	1,378,856	3	2	1
Davao City	highly-urbanized city	1,363,337	3	3	0
Leyte	province	1,327,313	3	5	-2
Isabela	province	1,275,251	3	4	-1
Maguindanao	province	1,273,715	3	2	1
Tarlac	province	1,243,449	3	3	0
Negros Oriental	province	1,231,904	3	3	0
Bohol	province	1,230,110	3	3	0
Albay	province	1,190,823	3	3	0
Bukidnon	province	1,190,284	3	3	0
Lanao del Sur	province	1,138,544	3	2	1
Cotabato	province	1,121,974	3	2	1
Cagayan	province	1,072,571	2	3	-1
Zamboanga del Sur	province	914,278	2	2	0
Zamboanga del Norte	province	907,238	2	3	-1
Sulu	province	849,670	2	2	0
Davao del Norte	province	847,440	2	2	0
Davao del Sur	province	822,406	2	2	0
Cebu City	highly-urbanized city	798,809	2	2	0
Zamboanga City	highly-urbanized city	774,407	2	2	0
Masbate	province	768,939	2	3	-1
South Cotabato	province	767,255	2	2	0
Misamis Oriental	province	748,791	2	2	0
Oriental Mindoro	province	735,769	2	2	0
La Union	province	720,972	2	2	0
Sorsogon	province	709,673	2	2	0
Capiz	province	701,664	2	2	0
Samar	province	695,149	2	2	0
Palawan	province	682,152	2	2	0
Sultan Kudarat	province	675,644	2	2	0
Taguig	highly-urbanized city	670,309	2	2	0
Bataan	province	662,153	1	2	-1
Compostela Valley	province	637,366	1	2	-1
Ilocos Sur	province	632,255	1	2	-1
Pasig	highly-urbanized city	617,301	1	1	0
Agusan del Sur	province	609,447	1	2	-1
Valenzuela	highly-urbanized city	568,928	1	2	-1
Cagayan de Oro	highly-urbanized city	553,966	1	2	-1
Parañaque	highly-urbanized city	552,660	1	2	-1
Northern Samar	province	549,759	1	2	-1
Ilocos Norte	province	547,284	1	2	-1
Zamboanga Sibugay	province	546,186	1	2	-1
Surigao del Sur	province	541,347	1	2	-1
Lanao del Norte	province	538,283	1	2	-1
Las Piñas	highly-urbanized city	532,330	1	1	0
Misamis Occidental	province	531,680	1	2	-1
General Santos	highly-urbanized city	529,542	1	0	1
Antique	province	515,265	1	1	0
Camarines Norte	province	513,785	1	2	-1
Makati	highly-urbanized city	510,383	1	2	-1
Bacolod	highly-urbanized city	499,497	1	1	0
Basilan	province	496,505	1	1	0
Aklan	province	495,122	1	1	0
Zambales	province	493,085	1	2	-1
Davao Oriental	province	486,104	1	2	-1
Sarangani	province	475,514	1	1	0
Muntinlupa	highly-urbanized city	452,943	1	1	0
Tawi-Tawi	province	450,346	1	1	0
Marikina	highly-urbanized city	424,610	1	2	-1
Occidental Mindoro	province	421,592	1	1	0
Iloilo City	highly-urbanized city	418,710	1	1	0
Surigao del Norte	province	409,468	1	2	-1
Eastern Samar	province	405,114	1	1	0
Pasay	highly-urbanized city	403,064	1	1	0
Nueva Vizcaya	province	397,837	1	1	0
Southern Leyte	province	390,847	1	1	0
Benguet	province	372,533	1	1	0
Malabon	highly-urbanized city	363,681	1	1	0
Agusan del Norte	province	314,027	1	2	-1
Iligan	highly-urbanized city	308,046	0	1	-1
Mandaluyong	highly-urbanized city	305,576	1	1	0
Baguio	highly-urbanized city	301,926	1	1	0
Lapu-Lapu	highly-urbanized city	292,530	1	1	0
Romblon	province	279,774	1	1	0
Navotas	highly-urbanized city	245,344	0	1	-1
Catanduanes	province	232,757	1	1	0
Abra	province	230,953	1	1	0
Marinduque	province	229,636	1	1	0
Aurora	province	187,802	1	1	0
Kalinga	province	182,326	1	1	0
Ifugao	province	180,711	1	1	0
Quirino	province	163,610	1	1	0
Guimaras	province	151,238	1	1	0
Biliran	province	150,031	1	1	0
Mountain Province	province	148,661	1	1	0
San Juan	highly-urbanized city	125,338	0	1	-1
Dinagat Islands	province	120,813	1	1	0
Apayao	province	103,633	1	1	0
Siquijor	province	87,695	1	1	0
Camiguin	province	81,293	1	1	0
Batanes	province	15,974	1	1	0
Totals		85,784,804	205	230	-25
Advised pop/district	442,713
Min. pop/district	250,000

Sources: Wikipedia -- Primary LGUs in the Philippines, 15th Congress of the Philippines.
Numbers in pink = less than the advised population per district; numbers in red = less than the legal minimum population per district.

There are some irregularities. Since previous Congresses divided the country indiscriminately through the years, we have an extra five seats. But it's five only seats, compared to the upcoming Congress where there are 230 district Congressmen and God knows how many sectoral representatives will be there (the total number of Congressmen fluctuate with every Congress).

There's a caveat with this: exactly how are we going to re-divide the country every census? Note that this provision has NEVER been implemented. Never. Americans have this problem in redistricting, but since they already know how, the question is who. The Cavite redistricting was via a Congressional act, and Dasmarinas would have had its own anyway even if the redistricting did not push through, plus the fact that the second (Bacoor) and third districts (Imus) are wholly composed of municipalities. State governments are in charge of how to redistrict their own state: they either do it via their state legislatures (which are partisan) or via a "non-partisan" redistricting committee.

I am not questioning the wisdom of redistricting in Cavite, or whether it was legal, for I believe there is no easy way in determining this question. In fact, there might be no way to answer if this was even proper. Perhaps this national reapportionment must be done now, and perhaps we should devise ways on how to do this.

Next: Party-lists.