What is legislation?

In a democracy, Parliament is sovereign and the laws it passes, known as Acts of Parliament or statutes, take precedence over any other source of law. Statutes can be amended or repealed by later legislation, so it is important not only to be able to find the legislation that applies to a particular situation, but also to find out whether it has been affected by a later enactment.

Primary and secondary legislation

Statutes or Acts of Parliament are known as primary legislation. A statute can also delegate to another person, usually a minister of the government, the power to enact secondary legislation, known as a statutory instrument. This usually takes the form of an order or regulations. Secondary legislation can also be amended or repealed, either by primary legislation (statutes) or a later statutory instrument.

Secondary legislation is also known as delegated or subordinate legislation. It is generally used for the following purposes:

  • To fill in or update details (such as the value of a fine) left out by primary legislation
  • To provide for the commencement or geographical extent of primary legislation
  • To provide detailed rules, regulations or a code of practice in a particular sphere of activity (such as road traffic regulations)
  • To provide rules of court

Orders in Council

Traditionally, orders in council were made by exercise of the royal prerogative in consultation with the Privy Council, and constitute a form of primary legislation. However, more recent orders in council are made by ministers of the crown exercising powers derived from statute, and are therefore secondary or delegated legislation. An example of the latter is the process by which ministers can give effect to provisions of European Union law that do not have direct effect.

Henry VIII powers

Occasionally a delegated power includes the power to use secondary legislation to amend primary legislation. Such powers are known as ‘Henry VIII powers’ in reference to the Tudor king’s supposed preference for legislating directly by proclamation rather than through Parliament.

Geographical extent

A statute may be expressed to cover only part of the United Kingdom. This is what is described as its geographical extent.

Historically, it has been common for the UK Parliament to pass legislation applying only to one of the three main jurisdictions, such as Scotland, Northern Ireland, or England and Wales. Since devolution, both the Scottish Parliament and the Welsh Assembly have had the power to pass legislation applying only within those countries. But legislation of the UK Parliament may now also be expressed as only applying only to Wales, or only to England.


All UK statutes are written and published in English, while those enacted by the National Assembly for Wales are written and published in both Welsh and English.

Under a project announced in December 2016, pre-devolution statutes applying in Wales are to be codified by the Welsh government and republished in both Welsh and English on a dedicated website.

Updated 5 October 2018

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