Article 2(1) lets any person who alleges that an enactment or an act or omission is inconsistent with the Constitution bring an action for a declaration.
The 31st December case, NPP v Attorney-General, shows the approach in practice: the plaintiff did not need a personal interest beyond citizenship.
Standing is not the same as rights enforcement. A claim to vindicate one’s own rights is still an Article 33 matter for the High Court.