Then Executive Secretary  petitioner Eduardo Ermita assailed via certiorari the  writ of preliminary injunction granted by public respondent Judge Jenny Lind R. Aldecoa Delorino, then Presiding Judge of  the Regional Trial Court of Makati City, Branch 137, by Omnibus Order ¹ dated February 6, 2007 in favor of private respondent Association of Petrochemical Manufacturers of the Philippines  (APMP or private respondent) denying petitioner's Motion to Dismiss and enjoining the government from implementing Executive Order No. 486.

Executive Order No. 486 (E.O. 486) issued on January 12, 2006 by then President Gloria Macapagal-Arroyo reads:

LIFTING THE SUSPENSION OF THE APPLICATION OF THE TARIFF REDUCTION SCHEDULE ON PETROCHEMICALS AND CERTAIN PLASTIC PRODUCTS UNDER THE COMMON EFFECTIVE PREFERENTIAL TARIFF (CEPT) SCHEME FOR THE ASEAN FREE TRADE AREA (AFTA)

WHEREAS, Executive Order 234 dated 27 April 2000, which implemented the 2000-2003 Philippine schedule of tariff reduction of products transferred from the Temporary Exclusion List and the Sensitive List to the Inclusion List of the accelerated CEPT Scheme for the AFTA, provided that the CEPT rates on petrochemicals and certain plastic products will be reduced to 5% on 01 January 2003;

WHEREAS, Executive Order 161 issued on 9 January 2003 provides for the suspension of the application of the tariff reduction schedule on petrochemicals and certain products in 2003 and 2004 only;

WHEREAS, the government recognizes the need to provide an enabling environment for the naphtha cracker plant to attain international competitiveness;

WHEREAS, the NEDA Board approved the lifting of the suspension of the aforesaid tariff reduction schedule on petrochemicals and certain plastic products and the reversion of the CEPT rates on these products to EO 161 (s.2003) levels once the naphtha cracker plant is in commercial operation;

NOW, THEREFORE, I, GLORIA MACAPAGAL-ARROYO, President of the Republic of the Philippines, pursuant to the powers vested in me under Section 402 of the Tariff and Customs Code of 1978 (Presidential Decree No. 1464), as amended, do hereby order:

SECTION 1.  The articles specifically listed in Annex "A" (Articles Granted Concession under the CEPT Scheme for the AFTA) hereof, as classified under Section 104 of the Tariff and Customs Code of 1978, as amended, shall be subject to the ASEAN CEPT rates in accordance with the schedule indicated in Column 4 of Annex "A".  The ASEAN CEPT rates so indicated shall be accorded to imports coming from ASEAN Member States applying CEPT concession to the same product pursuant to Article 4 of the CEPT Agreement and Its Interpretative Notes.

SECTION 2.  In the event that any subsequent change is made in the basic (MFN) Philippine rate of duty on any of the article listed in Annex "A" to a rate lower than the rate prescribed in Column 4 of Annex ""A, such article shall automatically be accorded the corresponding reduced duty.

SECTION 3. From the date of effectivity of this Executive Order, all articles listed in Annex "A" entered into or withdrawn from warehouses in the Philippines for consumption shall be imposed the rates of duty therein prescribed subject to qualification under the Rules of Origin as provided for in the Agreement on the CEPT Scheme for the AFTA signed on 28 January 1992.

SECTION 4.  The Department of Trade and Industry, in coordination with National Economic and Development Authority, the Department of Finance, the Tariff Commission and the Bureau of Customs, shall promulgate the implementing rules and regulations that will govern the reversion of the CEPT rates on petrochemicals and plastic products to EO 161 (s.2003) levels once the naphtha cracker plant is in commercial operation.

SECTION 5. All presidential issuances, administrative rules and regulations, or parts thereof, which are contrary to or inconsistent with this Executive Order are hereby revoked or modified accordingly.

SECTION 6. This Executive Order shall take effect immediately following its complete publication in two (2) newspapers of general circulation in the Philippines.

Done in the City of Manila, this 12th day of January in the year of Our Lord Two Thousand and Six.  (emphasis supplied)

The above issuance in effect reduces protective tariff rates from 10% to 5% on the entry of inexpensive products, particularly plastic food packaging, from ASEAN Free Trade (AFTA) member countries into the Philippines.

APMP, an organization composed of manufacturers of petrochemical and resin products, opposed the implementation of E.O. 486.  Contending that the E.O. would affect local manufacturers, it filed a petition before the RTC of Makati, docketed as Civil Case No. 06-2004, seeking the declaration of its unconstitutionality for being violative of Sec. 4 of Republic Act No. 6647 which prohibits the President from increasing or reducing taxes while Congress is in session ² and Sec. 402(e) ³ of the Tariff and Customs Code.  It thereupon prayed for the issuance of a writ of preliminary injunction to enjoin its implementation.

Petitioner contends that public respondent gravely abused her discretion in assuming jurisdiction over the petition for prohibition and granting the writ of preliminary injunction as the exercise of the quasi-legislative functions of the President cannot be enjoined.  He avers that writs of prohibition lie only against those persons exercising judicial, quasi-judicial or ministerial functions.

By granting injunctive relief, petitioner contends that public respondent effectively preempted the trial of and pre-judged the case, given that what private respondent seeks is to stop the implementation of E.O. 486.  Further, petitioner contends that the grant of injunctive relief was not supported by fact and law, for what APMP sought to be protected was future economic benefits