2.1.1 – The Nature and Sources of the UK constitution
Common Law is an important source of the UK constitution. Common Law is otherwise known as ‘judge made law’ and it is the body of law that is made up from the precedents of previous court cases that have gone before. As a result of this, Common Law is evolutionary, it changes and develops through time as society evolves. So how does this work, and why is it fundamental to the operation of the UK constitution?
How does Common Law work?
Common law is a body of law that evolves through the decisions of courts and tribunals. When a judgement is made by a court, it creates a precedent that will be followed by future judges. Common law works under a principle of Stare Decisis (to stand my things decided). This means that common law is naturally conservative and slow to change, as judges are obligated to follow precedents unless they can clearly show that those legal precedents are wrong. Within a common law system, lower courts must also follow the decisions made by higher courts.
Despite the importance of precedent, common law can change. A good example occurred in 2016 with the issue of ‘joint enterprise’. Joint enterprise is a legal concept in which multiple individuals can be held liable for the same criminal offence if their actions collectively led to that crime being committed. In order to find someone guilty under the joint enterprise doctrine a prosecution had to prove that:
- A person assisted the commission of an offence.
- That person deliberately acted and knew they may be assistance the offence.
- That the person foresaw a substantial risk of the eventual outcome.
- That they intended to assist in the act.
However, in 2016 the Supreme Court heard the case of R v Jogee. In this case the Supreme Court found that the law had taken a wrong-turn in the past. They concluded that the standard used to convict under joint enterprise was unsafe. The court decided that it was wrong to convict someone simply because they foresaw that a co-defendant might commit a crime. Instead, they clarified that there must be proof the person actively encouraged or assisted the crime. This ruling significantly changed the way joint enterprise is assessed in British law. This is an example of how common law can change through time.
What is the relationship between Common Law and Statute Law?
Common Law is inferior to Statute Law in Britain. This is because in Britain there is a doctrine of parliamentary sovereignty, meaning that no body can overrule Parliament. This means that if Parliament pass a law (called a Statute) it takes precedence over any Common Law rulings.
For example, the Corporate Manslaughter and Corporate Homicide Act (2007) created a new criminal offence of corporate manslaughter. This Act was passed because under Common Law it had been difficult to prosecute a company for manslaughter due to a legal principle called the ‘identification doctrine’. This doctrine said that only senior officials can be held legally accountable for actions of a company, but this limited liability as it was often difficult to prove. The Act made it easier to find companies criminally liable.
Despite the primacy of Statute Law, it cannot function adequately without Common Law. This is because it would be impossible for Parliament to be able to foresee every eventuality and every implication of any law that they pass. Given this, it is therefore essential that Common Law ‘fills the gaps’ in Statute Law.
For example, in 2010, the Equality Act was passed in the UK. This made it unlawful to discriminate against someone based on nine protected characteristics (unless that discrimination was a ‘proportionate means to achieve a legitimate aim’). The Act puts a duty on service providers to make ‘reasonable adjustments’ for someone who is disabled. However, the term reasonable adjustment is subjective and case specific. Consequently, it is judges who have to adjudge on any failure to make reasonable adjustments and therefore create case law that judges can use when looking at future cases.
Murder is an example of a Common Law offence. Murder was seen as a crime long before the existence of Parliament and therefore has existed in Common Law since at least Anglo-Saxon Britain. However, there have been some occasions when Parliament has stepped in to ensure certain issues have more clarity. An example of this is through the enactment of the Homicide Act (1957). This law largely abolished the doctrine of ‘constructive malice’, whereby someone could be charged with murder if they killed someone unintentionally whilst committing another crime. The Homicide Act also introduced a defence of ‘dismissed responsibility’, whereby the judgement of the person committing the crime was impaired by a circumstance beyond their control, for example a mental health issue.
The amendment was largely in reaction to a number of high profile cases, including that of Derek Bentley in 1953 and Ruth Ellis in 1955, both of whom had subsequently been hanged.
Derek Bentley was convicted of murder in 1953 after the death of a police officer named PC Miles. Bentley and his co-defendant, Christopher Craig, had been attempting to burgle a warehouse when PC Miles intervened. Craig shot Miles dead, but was not executed as he was a juvenile. Bentley, however, was hanged after the jury heard he had shouted ‘let him have it’ whilst Craig wrestled with Miles. The prosecution interpreted this as an incitement to murder and the 19 year-old was hanged, calling much public outrage.
Ruth Ellis was a model. She was the last woman to be hanged in Britain. She was convicted of murdering her partner David Blakeley. She was in an abusive relationship and had a daughter that Blakely would not acknowledge. There was no doubt Ellis intended to kill Blakeley, however, it is clear she did so under some duress.
Common Law is built up from a huge range and number of judicial precedents. Sometimes, Common Law can become hazy and sometimes does not keep up with the developing attitudes of society. In this case, it is up to Parliament to legislate to clear up the matter.
A good example of this is found in the case of Wilkinson vs. Kitzinger. Sue Wilkinson and Celia Kitzinger married in Canada in 2003 after being a couple for 13 years. Wilkinson still lived and worked in England. In 2004 the UK Civil Partnership Act came into force, allowing same-sex civil partners similar legal right to married heterosexual couples. However, as Wilkinson and Kitzinger were already married, they wished their marriage to be recognised in the UK.
The case went to the High Court in 2006. The High Court announced that the Wilkinson and Kitzinger’s relationship would be treated as a civil partnership, not a marriage. The court said that by “longstanding definition and acceptance” marriage was between a man and a woman.
This led, in part, to a societal discussion over the merits of Same-Sex Marriage and the antiquated way in which common law was being applied. In 2013 Parliament cleared up the issue by passing the Marriage (Same Sex Couples) Act which equalised heterosexual and homosexual marriage.
What are the strengths of a system of Common Law?
- Common law offers flexibility
Common law systems are highly adaptable and therefore can quickly respond to societal changes. Whilst judges rely on precedent to make their decisions, they can also apply them to new and changing societal situations.
2. It offers predictability
As common law is based on precedent, it offers significant predictability and consistency. Legal disputes can be easily predicted and this often leads to settlements outside of court, rather than expensive and time-consuming litigation.
3. It creates a detailed body of law
The common law system provides a detailed body of law. When judges make their decisions, they are deliberately detailed and cite the previous cases they have relied on. This contributes to a better legal system overall.
4. It relies on judicial expertise
Judges become experts in particular areas of law. This creates trust in the judgements that they are handing down.
5. Judges can act to protect rights
Common law emphasises the protection of individual rights. Judges can therefore play a fundamental role in making sure this is done.
What are the limits of Common Law?
- Common law can be extremely complex
Common law often relies on complex bodies of law that can be very difficult to navigate. This is particularly the case for ordinary citizens without legal training.
2. It can be seen to be reactive, rather than proactive
Common law evolves through reactions to cases – it isn’t proactive. This means that it can be very slow to address new issues and this can lead to gaps in the law.
3. It is naturally conservative in nature
As a result of principles like stare decisis, common law is naturally conservative in nature. This can delay the development of law.
4. It can accentuate judicial bias
Judges play a significant role in shaping common law. Their personal and philosophical biases may influence there decisions meaning that the body of law is less impartial than it ideally would be.
5. It can be piecemeal
Common law can often rely on piecemeal judicial decisions as they have not been codified into statute law. This can lead to a less organised system of law comparted to those that use more detailed statutes and codes.
Overall, there are undoubtedly problems with common law. It relies on the judicial decisions of judges, who are not elected and therefore not accountable to the public. A concern is also often raised that judges come from a predominantly conservative background, with many being Oxbridge educated, which therefore imbues a conservative political bias in judicial decisions. However, it remains an essential part of the effective operation of the UK constitution and the upholding of the Rule of Law.
Article Summary
Common law is essential to the the legal system and the rule of law in the UK. It works on a system of judicial precedent, where the legal system is built up over case law that goes back potentially a thousand years. Common law cannot work on its own, however, a statute law is the mechanism to give democratic legitimacy to aspects of the legal system. Common law, however, can serve to ‘fill the gaps’ that statute law unavoidably leaves.
Glossary of Terms
Common Law – This law is made by taking into account the previous conclusions of judges. This creates a judicial precedent for judges to use in the future. This is often referred to as judge made law. Importantly, it ‘fills the gaps’ left by Statute Law.
Judicial Precedent – A legal principle that follows that once a court makes a decision the standard set should be followed by other judges unless there is a compelling reason to diverge from the previous judgement.
Stare Decisis – A legal principle that says that points of law should be determined by precedent and that precedent should only change if necessary.
Statute Law – Laws created via Act of Parliament. They are considered the superior form of law.
Last Updated – 20.10.25