〜にせよ〜にせよ／〜にしろ〜にしろ

Meaning

Cites two cases and states that in either case the conclusion is the same. Prefaces with "either way," as in 「行くにせよ行かないにせよ」 (whether you go or not).

Examples

参加するにせよしないにせよ、返事だけは早めにしてほしい。 Whether you participate or not, please reply as soon as possible.
賛成にしろ反対にしろ、理由を明確にすべきだ。 Whether for or against, you should state your reasons clearly.