There are many advantages to the purposive approach. Firstly, it gives effect to Parliaments intentions and avoids injustice, so the judges can avoid obvious absurdities and injustives so enables them to comply with Parliamentary sovreignity by doing what Parliament would have wanted; even though it’s ignoring the clear meaning of the words Parliament used. For example, in Coltman V Bibby Tankers when they had to interpret the word ‘equipment’. Secondly, it give flexibility and can fill in the gaps, so looks to the spirit of the law rather than to the letter, therefore leaning towards a potentially just approach. However words can be ommitted/added if the court were certain of the act, if it was draftsmen/parliaments mistake that the act was written wrong, or that the judges were sure of the substance of the provision Parliament would have made. For example in Inco Europe Ltd. v First Choice Distribution 2000 H of L.
Thirdly, it allows for new technology/developments, and also allows the judges to keep the legislation in line with modern thinking and new technological developments, for example in R (Quintaville) v Sec of State for Health 2002. The purposive approach also allows our judges to comply with the Human Rights Act 1998. Under s3 of this Act, judges must try to reach an interpretation that doesn’t breach human rights. A literal interpretation might reach a result that breached human rights. Instead, provided a different interpretation doesn’t go against the whole purpose of the legislation, the judges can interpret the Act more creativley (Ghaidan v Godin-Mendoza).
The last advantage is that the purposive approach is consistent with the European approach. So it allows the judges to fulfil our obligations under EU Law. (Bulmer v Bolinger)
There are also many disadvantages to the purposive approach. Firstly, it involves too much judicial law making as it allows them too much freedom as seen in Royal College of Nursing v DHSS 1981, the judges weren’t interpreting the Act but ‘redrafting it with a vengeance’. Secondly. it creates uncertainty as it is subjective law making and is difficult to anticipate when judges will decided to use the purposive approach (Bentham). It isn’t possible to know for sure what result using the purposive approach might lead to (Yemshaw).
Finally, it is difficult to discover Parliaments intentions. It relies of looking for Parliaments purpose, yet this may not even exist.