The United Kingdom constitution – a mapping exercise
A briefing paper which "maps" (or summarises) the main elements of the United Kingdom's uncodified constitution.

This Briefing Paper discusses statutory instruments (SIs). In particular, it describes what they are and also the parliamentary procedures related to them.
House of Commons Background Paper: Statutory Instruments (724 KB , PDF)
Acts of Parliament (primary legislation) often confer powers on Ministers to make more detailed orders or regulations by means of statutory instruments (SIs), also known as secondary, subordinate or delegated legislation. They are as much a part of the law as an Act.
In the region of 3,500 SIs are made each year. Many SIs are not subject to any parliamentary procedure, and simply become law on the date stated. Whether they are subject to parliamentary procedure, and if so which one, is determined by the parent Act.
The majority of SIs subject to parliamentary control automatically come into force but Parliament has the power to annul them within a particular period after they are laid (the negative resolution procedure). A smaller number of SIs require the approval of Parliament before they can be made and brought into force (the affirmative resolution procedure).
On 22 October 2015, the House of Commons amended its Standing Orders to give MPs representing seats in England or England and Wales the power to veto Government legislation that affected only those parts of the country, and was the subject of devolved legislative competence. The House agreed that SIs which the Speaker certified affected only England or only England and Wales and were within devolved legislative competence would be subject to double majority voting, if the question on any motion relating to the instrument was the subject of a division. The Standing Orders state that a motion relating to a certified SI
… shall be agreed to only if, of those in the division-
(a) a majority of Members, and
(b) a majority of Members representing qualifying constituencies,
vote in support of the motion.
House of Commons Background Paper: Statutory Instruments (724 KB , PDF)
A briefing paper which "maps" (or summarises) the main elements of the United Kingdom's uncodified constitution.
On Wednesday 25 June 2025, there will be an Estimates Day debate on the spending of the Ministry of Justice. This debate pack contains details of the latest estimates and previous expenditure, background material, and suggestions for further reading.
A briefing paper on the office and functions of the Prime Minister