Omnibus Election Code
Section 189. Representatives of the registered political parties in the verification and distribution of official ballots and election returns. - The ruling party and the dominant opposition party or their respective duly authorized representatives in the different provinces, cities and municipalities, shall submit the names of their respective watchers who, together with the representatives of the Commission and the provincial, city and municipal treasurer shall verify the contents of the boxes containing the shipment of official ballots, election returns and sample official ballots received by the said treasurers. The provincial treasurers shall keep a record of their receipt and distribution to each municipal treasurer, while the city and municipal treasurer shall each keep a record of their distribution to the board of election inspectors.