Collective cabinet responsibility evolved following New Zealand’s change to a mixed-member proportional (MMP) electoral system in 1996 and the demands of multi-party government. The issue of unanimity has been the source of most of the changes in the post-MMP period.
The coalition between National and New Zealand First which began in 1996 was plagued by conflicts and personality differences from the start. It collapsed in 1998 when the New Zealand First members walked out of cabinet in a disagreement over the sale of the government’s share in Wellington airport.
Agreeing to disagree
That some sort of change was needed was demonstrated by the demise of the National–New Zealand First coalition during the National-led government of 1996–99. Having adopted a strict interpretation of collective responsibility, it was unable to accommodate the public expression of significant differences over policy. Accordingly the Labour–Alliance government adjusted the convention in 1999 to allow the establishment of agree-to-disagree procedures.
Partial application of collective responsibility
The Labour-led minority coalition government formed in October 2005 further modified the convention of collective responsibility. That government was built on four separate agreements between political parties.
The two agreements on confidence and supply with the New Zealand First and United Future parties gave the leader of each of these two parties, Winston Peters and Peter Dunne respectively, ministerial positions. While the Cabinet manual provisions relating to collective responsibility applied to each minister, they did so only in respect of their particular portfolio responsibilities. In every other situation the agree-to-disagree provisions of the Cabinet manual applied.
Neither was a member of any cabinet committee – other ministers presented papers on their behalf. The two ministers appeared on the ministerial list as ‘Ministers Outside Cabinet from other Parties with Confidence and Supply Agreements’.
Agreeing to cooperate
The 2005 cooperation agreement between Labour and the Green Party led to some changes in the way cabinet worked. The Greens agreed not to oppose the government on confidence and supply, and in return were able to be involved in policy development and implementation arrangements (including budget deliberations) in a number of specified policy areas. This meant Green Party representatives were able to attend cabinet committee meetings and participate in discussions.
The pattern established by the 2005–2008 Labour-led government was followed by the National-led administration formed in 2008. In 2017 Labour and New Zealand First formed a minority coalition government that was supported by the Green Party on matters of confidence and supply. The Greens' three ministers were outside cabinet.