Vested Rights in Procedural Rules

The rule in this jurisdiction is that one does not have a vested right in procedural rules. While the rule admits of certain exceptions, such as when the statute itself expressly or by necessary implication provides that pending actions are excepted from its operation, or where to apply it would impair vested rights, petitioners failed to show that application of A.O. No. 17 to their case would cause injustice to them (Gemma P. Cabalit Vs. COA-Region VII/Filadelfo S. Apit Vs. COA, Legal and adjuciation, Region VII/Leonardo G. Olaivar, etc. Vs. Hon. Primo C. Miro, etc., et al., G.R. Nos. 180326/180341/180342. January 17, 2011).