Separation of Powers

• The doctrine of separation of powers is a constitutional theory that was first put forward by eighteenth century political theorist Montesquieu. He argued that there are 3 primary functions (arms) of the State; the legislature (Parliament who make the laws); the executive (Government who administer the laws) and the judiciary (who interpret and enforce the laws). This principle is designed to prevent the concentration of power in one body and to ensure a system of checks and balances.
• Under the doctrine of separation of powers, it is argued that the only way to protect the liberty of citizens is to keep the 3 arms of the state separate and independent of each other. They shouldn’t interfere in the functions of the others. If each function is exercised by independent and separate bodies, each keeps a check on the others and limits the power of any one group. This will help to avoid a dictatorship and situations like when Germany was run by Hitler and ensure fair and impartial justice is delivered as no one person/body holds all the power in society aiding democracy.
• Under this theory, individuals should not be members of more than one function or ‘arm’ of the state.
• Some countries, such as the USA, have a written constitution that sets this out but this does not exist in the UK.
• Although in the UK there are 3 separate arms of state, the separation is not strict and there is still some overlap. Ministers (part of the executive) sit in Parliament (the legislature) and are active in the law making process. Until the Constitutional Reform Act 2005, the Lord Chancellor had roles in all three branches. However, reforms such as the creation of the Supreme Court in 2009 have strengthened the separation, especially between the judiciary and the other branches
• Overall, the doctrine promotes accountability and limits the risk of tyranny by ensuring that power is not concentrated in one institution.