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Statutory instruments procedure in the House of Commons

How statutory instruments (SIs) work in the House of Commons.

SIs are the most frequently used type of secondary legislation. Secondary legislation is used to add information or make changes to an existing Act of Parliament.

Most SIs must be considered by both Houses of Parliament before becoming law, but SIs relating only to financial matters are only considered by the Commons.

They generally pass through the Commons under one of two procedures, affirmative or negative. The procedure an SI follows is determined by its parent Act.

Affirmative procedure

Most SIs subject to the affirmative procedure are laid in the form of a draft SI. They are considered by the Joint Committee on Statutory Instruments (JCSI). The role of this committee is to scrutinise the SI to ensure it is legal and does not go beyond the powers specified in the parent Act.

Next, the SI will be automatically referred to a Delegated Legislation Committee [DLC]. These committees have 16-18 members. Any MP can attend and speak but only members of the DLC can vote. A DLC considers an SI but does not have the power to stop it. In some rare cases the SI is not referred to a committee, but is debated in the Commons Chamber if it is of particular interest.

Once the SI has been debated by a committee, it needs final approval by the Commons before being ‘made' (signed by the Minister) and becoming law.

On rare occasions when changes to the law are required urgently, made affirmative SIs can be used. Under the made affirmative procedure, if the SI is not approved by Parliament within a set time limit (usually 28 or 40 days), the change to the law is reversed.

This flowchart gives an overview of the most common process for affirmative SIs:

It is very rare for an affirmative SI to not receive Commons approval, the last one which failed to do so was in July 1978.

Negative procedure

The majority of SIs are laid in Parliament under the negative procedure, either as made negative or draft negative. As with the affirmative procedure, negative SIs are scrutinised by the JCSI.

Negative SIs will become law on the date stated in the SI unless either House annuls (stops) them within a fixed 40-day period. If both Houses are not sitting for a period longer than four days, the time limit will pause.

Made negative SIs

Made negative SIs have already been signed by the Minister before they are laid in Parliament which means they will automatically become law unless objected to.

Made negative SIs can come into force before the 40-day period is up, and will be revoked if the SI is annulled. There is a convention that, where possible, a negative SI should be laid in Parliament at least 21 days before it comes into effect.

This flowchart gives an overview of the most common process for negative SIs:

Draft negative SIs

A small number of negative SIs are laid in draft and cannot be made (signed) if either House stops them within the 40-day period.

Process to stop a negative SI

Any MP may put forward a prayer motion to stop a negative SI.

Prayer motions usually take the form of an Early Day Motion, and if put forward within the 40-day period, one of the following will happen:

  • the Minister may choose not to take any action, in this case nothing more will happen and after the 40-day period ends the Commons has no further role and the SI remains law.
  • the Minister may table a motion to refer the SI to a DLC which will debate the motion.
  • the Government or Opposition may schedule time to debate and vote the SI in the Commons Chamber.

If a motion to annul (stop the SI) is agreed to in the Commons, the SI will be revoked. However, it is very rare for this to occur - the last time this happened was in October 1979.

An MP could put forward a prayer motion outside of the 40-day period, but this would only object to the SI, rather than stop it.

Find a statutory instrument

Once they have been laid in Parliament you can find SIs and follow their progress.  

The full text of SIs and related explanatory memoranda, which explain what the instrument does and why, are published on

Contact us for more information

Secondary legislation is complex and we want to answer all your questions. If you need further information please contact us.

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