Primary Legislation, Secondary Legislation and Statutory Instruments are all mechanisms through which law is enacted in the UK. In fact, primary legislation (that which follows the stages of a bill through both Houses) is rather rare. There would simply not be enough time to pass all law in this way. Indeed, this is borne out by the numbers.
For example, in the 2017-2019 parliamentary session there were 70 Acts of Parliament passed. However, in just 2018 alone, 1387 statutory instruments (secondary legislation) were enacted. It is clear that most law in the UK is not made by Parliament directly. So, given this, what are the different ways in which law is enacted in the UK?
What is Primary Legislation?

Primary legislation is that made directly through an Act of Parliament, following the full legislative process. A bill must go through both the House of Commons and the House of Lords before going to the Monarch for Royal Assent.
As Parliament is sovereign any primary legislation passed cannot be overturned by any other body other than Parliament. In addition, the ‘doctrine of implied repeal’ means that if it conflicts with an earlier piece of legislation, it automatically is seen to take precedence over it.
What is Secondary Legislation?

Secondary Legislation (also known as delegated legislation) is made by a person or body that have been delegated the power to do so by Parliament in primary legislation. Secondary Legislation is essential for the effective running of the government. It is simply not possible for Parliament to legislate through primary legislation for every decision that needs to be taken. This is where Secondary Legislation becomes so significant.
For example, in 2011 Parliament passed the Charities Act. One of the aims of this Act is for Parliament to decide the rules of who can and cannot be a charity. It would clearly not be possible for Parliament to carry out a detailed consideration of every case itself. Therefore, it delegates its power to the Charities Commission. Section 23 of the Charities Act (2011) gives the Commission the power to remove the status of a ‘charity’ to any organisation that it believes does not meet the standards required.
What is a Statutory Instrument?
Statutory Instruments are the most common way that secondary legislation is enacted with around 3,500 being passed per year. Statutory Instruments are usually created by Members of Cabinet in order to delegate another body or person to carry out an action. Statutory Instruments are all recorded and are scrutinised by Parliament. Each Statutory Instrument is scrutinised either via affirmative or negative resolution procedure:
Negative Resolution procedure: This is by far the most common way of scrutinising statutory instruments. In this procedure, any statutory instrument has to be laid before Parliament for 40 days and will automatically become law unless either House votes against it in that time.
In practice, this happens extremely very rarely. The last time a Statutory Instrument was voted against under this procedure was in February 2000.
Affirmative Resolution procedure: These SIs are much rarer. Under this procedure, the Houses must vote on the SI before it becomes active. They are usually used for the most controversial legislation, for example those that allow the government to increase its surveillance of citizens.
Under this procedure both Houses of Parliament must agree to the SI being enacted.

In order to try to enable parliamentary scrutiny there are three Select Committees that exclusively consider Statutory Instruments:
- Joint Committee on Statutory Instruments
- House of Commons Select Committee on Statutory Instruments
- Lords Committee on the Merits of Statutory Instruments
What is an Order-in-Council?
Orders-in-Council are decrees made by the Monarch on the advice of the Privy Council. Importantly, it is through Orders-in-Council that the governments Royal Prerogative powers are used. For example:
- Appointment of Government Ministers
- Ordering of Military Action
These are often controversial as, unlike with all other forms of law-making, there is no parliamentary scrutiny (although the passing of a Statute would overrule an Order-in-Council).
A good example for considering this issue is the directing of military force by the Prime Minister. Since 2003, it had begun to emerge as a convention that the Prime Minister should seek the authorisation of Parliament before engaging British Armed Forces in combat. However, in 2018 Theresa May ordered the British Air Force to make strikes against the Syrian Government of Bashar Al-Assad.

This led to then Labour Leader Jeremy Corbyn calling for Parliament to pass a ‘War Powers Act’, which explicitly limited the PMs Royal Prerogative powers as regards military action (a separate post will be written about this later in the week). Ultimately, whereas Acts of Parliament and Statutory Instruments have parliamentary scrutiny, the Royal Prerogative does not. This is shown through the prorogation controversy of 2019, where the Supreme Court, not Parliament, reversed the decision to prorogue parliament in September 2019.
Article Summary
Very little of the law that is passed is primarily legislation, the vast majority is secondary. In addition, powers carried out under the royal prerogative are enacted via an Order-in-Council. One of the issues that this creates is that very little law passed in the UK is fully scrutinised.
Key Terms
Royal Prerogative – Powers that used to belong to the Monarch but are now carried out by the Prime Minister or the Government.
Order-in-Council – The mechanism through which royal prerogative powers are enacted. Orders-in-Council do not have parliamentary scrutiny.
Primary Legislation – Legislation that goes through the full legislative process in both the House of Commons and House of Lords.
Secondary Legislation – Legislation that can be enacted by a Government Minister or another body after being enabled in primary legislation.
Statutory Instrument – Statutory Instruments are the most common form of secondary legislation and have to be either confirmed or rejected by Parliament.