The initial control Parliament exercises over delegated legislation is through the limits it sets in the parent/enabling Act. Only the people or body specified in the parent Act have power to make law, and the extent of that power is also specified.
Most statutory instruments must be laid before Parliament. This requires the statutory instruments to be laid on the table of the House. There are two methods of laying delegated legislation before Parliament:
First, there is the positive resolution procedure. This means that the statutory instrument must be approved by a vote in one or both Houses of Parliament within a specified time limit.
Secondly, there is the negative resolution procedure. This means that the statutory instrument is laid before Parliament, usually 40 days, and becomes law unless wither House votes to annul it.
The validity of a piece of delegated legislation can be challenged in the High Court through Judicial review procedure. The procedure by which the High Court may review a decision of a body (for example, a tribunal) to ensure that the rules of natural justice means, for example, that all parties be given the opportunity to put their case forward.
When the delegated is made beyond the powers conferred by the parent/enabling Act, the delegated legislation can be declared ultra vires by the court and void. Ultra vires is declared by court order when a delegated legislation is said to be "beyond the powers" set out in the parent Act.
There are two types of ultra vires: Procedural ultra vires is declareds when the piece of delegated legislation has not been made using the procedures specified in the parent Act. Substantive ultra vires is declared when the content of the delegated legislation is beyond the limits set out in the parent Act.