Ultra vires literally means, “beyond powers”. Ultra vires has two meanings- (1) substantive ultra vires where a decision has been reached outside the powers conferred on the decision taker; and (2) procedural ultra vires means the non-observance of the procedural norms by the rule-making authority and it may make the rule ultra vires due to non-observance of rule-making authority and hence become void.
When a subordinate legislation fails to comply with procedural requirements prescribed by the parent act or by general law, it is known as procedural ultra vires.
An administrative authority may be exercising a power for an authorized purpose but, if it fails to follow a required procedure, its actions will be open to challenge. The authority here may ‘doing the right thing’ but it is doing it ‘in the wrong way’ This is the concept of ‘procedural ultra vires’.