Estoppel on questions of jurisdiction applies to NLRC

Anent the matter on jurisdiction of the NLRC, the issue was mooted by petitioners' active participation in the proceedings below. In Marquez vs. Secretary of Labor, the Court said: "x x x. The active participation of the party against whom the action was brought, coupled with his failure to object to the jurisdiction of the court or quasi-judicial body where the action is pending, is tantamount to an invocation of that jurisdiction and a willingness to abide by the resolution of the case and will bar said party from later on impugning the court or body's jurisdiction." [G.R. No. 105396. November 19, 1996]