QUISUMBING, J.: rny

For review is the decision1 [Rollo, pp. 15-18.] of the Court of Appeals, dated August 3, 1994 and its resolution2 [Id. at p. 19.] dated December 8, 1994 in CA - G.R. SP No. 32473. Said decision dismissed the prohibition case brought by the petitioners against respondent officials of the Municipality of San Juan to stop the enforcement of Tax Ordinance Nos. 87, 91, 95, 100 and 101.

The factual antecedents are as follows:

The Sangguniang Bayan of San Juan, Metro Manila implemented several tax ordinances as follows:

On May 21, 1993, petitioners filed an appeal with the Department of Justice assailing the constitutionality of these tax ordinances allegedly because they were promulgated without previous public hearings thereby constituting deprivation of property without due process of law.

On June 10, 1993, respondent Secretary of Justice dismissed the appeal for having been filed out of time. Citing Section 187, R.A. No. 7160, he said:

Undaunted, petitioners filed with the Court of Appeals a petition for certiorari and prohibition (CA-G.R. SP No. 32473). But respondent court affirmed the decision of the Secretary. On December 8, 1994, the motion for reconsideration filed by the petitioners was denied for lack of merit.

Hence, the present petition for review, raising the following questions:

In our view, the pertinent issues for our resolution now are:

1.......Whether or not the Court of Appeals erred in affirming the decision of the Secretary of Justice who dismissed the prohibition suit, on the ground that it was filed out of time?

2.......Whether or not lack of mandatory public hearings prior to enacting Municipal Ordinance Nos. 87, 91, 95, 100 and 101 render them void on the ground of deprivation of property without due process?

3.......Whether or not the constitutional validity of Sec. 187 of the Local Government Code could be raised for the first time on appeal? Kyleä

According to petitioners, respondent Secretary erred in declaring that they failed to file their appeal on time. Also, they assail Municipal Ordinance Nos. 87, 91, 95, 100 and 101, for alleged failure of the Municipal Council of San Juan to conduct mandatory public hearings. Because of this, they claim the ordinances are inoperative, as though they were never passed. Consequently, no prescriptive thirty-day period to question the validity of the ordinance could toll to bar their appeal to the Department of Justice.

Sec. 187 of R.A. 7160, cited by respondent Secretary, provides as follows:

Clearly, the law requires that the dissatisfied taxpayer who questions the validity or legality of a tax ordinance must file his appeal to the Secretary of Justice, within 30 days from effectivity thereof. In case the Secretary decides the appeal, a period also of 30 days is allowed for an aggrieved party to go to court. But if the Secretary does not act thereon, after the lapse of 60 days, a party could already proceed to seek relief in court. These three separate periods are clearly given for compliance as a prerequisite before seeking redress in a competent court. Such statutory periods are set to prevent delays as well as enhance the orderly and speedy discharge of judicial functions.5 [Agpalo, Statutory Construction, Third Edition 1995, p. 266.] For this reason the courts construe these provisions of statutes as mandatory.6 [Ibid., citing Shioji vs. Harvey, 43 Phil. 333 (1922); Alvero vs. De la Rosa, 76 Phil. 428, 434 (1946)]

A municipal tax ordinance empowers a local government unit to impose taxes. The power to tax is the most effective instrument to raise needed revenues to finance and support the myriad activities of local government units for the delivery of basic services essential to the promotion of the general welfare and enhancement of peace, progress, and prosperity of the people.7 [Mactan Cebu International Airport Authority vs. Marcos, 261 SCRA 667, 690 (1996)] Consequently, any delay in implementing tax measures would be to the detriment of the public. It is for this reason that protests over tax ordinances are required to be done within certain time frames. In the instant case, it is our view that the failure of petitioners to appeal to the Secretary of Justice within 30 days as required by Sec. 187 of R.A. 7160 is fatal to their cause. Kycalrâ

On the second issue, petitioners allege that the Sangguniang Bayan of San Juan did not comply with the prescribed procedure for enacting an ordinance because they failed to conduct public hearings.

In Figuerres vs. Court of Appeals,8 [G.R. No. 119172, March 25, 1999.] where the municipality failed to conduct public hearings prior to enacting the revisions on the schedule of fair market values and assessment level of classes of real estate properties, the Court said:

We find Figuerres instructive. Petitioners have not proved in the case before us that the Sangguniang Bayan of San Juan failed to conduct the required public hearings before the enactment of Ordinance Nos. 87, 91, 95, 100 and 101. Although the Sanggunian had the control of records or the better means of proof regarding the facts alleged, petitioners are not relieved from the burden of proving their averments.10 [People vs. Pajenado, 31 SCRA 812, 817 (1970)] Proof that public hearings were not held falls on petitioners’ shoulders. For failing to discharge that burden, their petition was properly dismissed. CalrkyÓ

In any event, for the purpose of securing certainty where doubt would be intolerable, it is a general rule that the regularity of the enactment of an officially promulgated statute or ordinance may not be impeached by parol evidence or oral testimony either of individual officers and members, or of strangers who may be interested in nullifying legislative action.11 [73 Am Jur 2d, Statutes, Sec. 81.] This rule supplements the presumption in favor of the regularity of official conduct which we have upheld repeatedly, absent a clear showing to the contrary.

Finally, on the validity of Section 187 of R.A. 7160, the Local Government Code, we must stress that the constitutionality of an act of Congress will not be passed upon by the Court unless at the first opportunity that question is properly raised and presented in an appropriate case, and is necessary to a determination of the case, particularly where the issue of constitutionality is the very lis mota presented.12 [National Economic Protectionism Association vs. Ongpin, 171 SCRA 657, 665 (1989); People vs. Vera, 65 Phil. 56, 57 (1937); Dumlao vs. Comelec, 95 SCRA 392, 403 (1980)] The constitutional validity of a statutory provision should not be entertained by the Court where it was not specifically raised below, insisted upon, and adequately argued.13 [City of Baguio vs. Marcos, 27 SCRA 342, 351-352 (1969)] Moreover, given the circumstances in this case, we find no genuine necessity to dwell on the issue of constitutional invalidity of Section 187 in relation to issue of valid enactment of the subject ordinances, as shown in the foregoing discussion. Suffice it now to say that, having resolved the first and second issues, we find no grave abuse of discretion nor reversible error in the decision of the respondent appellate court. Further constitutional scrutiny of Section 187 is unwarranted.

WHEREFORE, the present petition is DISMISSED for lack of merit and the assailed decision of the Court of Appeals is AFFIRMED. No pronouncement as to costs.