Although interveners are often considered to have the potential to undermine the traditional adversarial system by favouring one of the parties, their involvement can also contribute to clarifying the law, benefiting a greater number of people than simply the parties to the litigation. This is particularly likely to be the case in the area of human rights where the courts are increasingly required to deal with complex new concepts.

The purpose of this project was to examine the role that interveners have played in human rights cases in New Zealand and whether the quality of decision making could be said to have improved as a result. Human rights law was selected as a case study as a result of the amendments to the Human Rights Act in 2001 that were designed to encourage the Human Rights Commission to take a more proactive role in the development of human rights jurisprudence where there was a need to settle important questions of law. The authors were also interested in whether, if there was demonstrable evidence of increasing third party involvement, there could be better guidance on how to intervene in order to facilitate public interest litigation and increase understanding of human rights and the rule of law generally.