The post of deputy prime minister was formally established in 1949. Eighteen individuals have held the position (with one of them doing so twice, and one doing so thrice) and of those people: Holyoake, Marshall, Watt, Muldoon, Palmer, Clark and English have eventually served as
prime minister. The deputy prime minister has always been a member of the
Cabinet and has always held at least one substantive portfolio. The deputy prime minister "...can, if necessary" exercise the statutory and constitutional functions and powers of the prime minister if the prime minister is unavailable or unable. They can also do the same as
acting prime minister, in consultation with the prime minister if it is appropriate and practicable. The deputy prime minister can also temporarily act as interim prime minister until the leadership of the government is determined in some cases, like the death of the prime minister. The position was most commonly held by the deputy leader of the largest party, but since the adoption of the
MMP electoral system in 1996 and the greater frequency of
coalition governments in New Zealand, the role may instead go to the leader of a junior government party. This has occurred three times with
Winston Peters, leader of
New Zealand First; once with
Jim Anderton, leader of the
Alliance; and once with
David Seymour, leader of
ACT New Zealand. Twice, the Labour Party has appointed a senior minister who was not the deputy party leader as the deputy prime minister (
Grant Robertson and
Carmel Sepuloni). Little scholarly attention has focused on deputy prime ministers in New Zealand or elsewhere. In 2009, an article by Steven Barnes appeared in
Political Science where nine 'qualities' of deputy prime ministership were identified: temperament; relationships with their Cabinet and caucus; relationships with their party; popularity with the public; media skills; achievements as deputy prime minister; relationship with the prime minister; leadership ambition; and method of succession. Barnes conducted a survey of journalists, academics, and former members of parliament to rank New Zealand deputy prime ministers up to that time since 1960. Across the nine deputy prime minister 'qualities',
Don McKinnon achieved the number one ranking, followed by
Brian Talboys,
Michael Cullen, and
Jack Marshall. In a second 'overall' ranking, Cullen was ranked number one, followed by Talboys, McKinnon, and Marshall. Winston Peters,
Jim Anderton, and
Bob Tizard were ranked lowest in both sections of the survey. ==List of deputy prime ministers of New Zealand==