publicly criticise the party. In late 1992, when the National Party was considering possible candidates for the elections in the following year, it moved to prevent Peters from seeking renomination (under any banner). In Peters v Collinge, Peters successfully challenged the party's actions in the High Court, and in early 1993, he chose to resign from the party and from Parliament. This prompted a by-election in Tauranga some months before the scheduled general election. Peters stood in Tauranga as an independent and won easily. Fourth National Government (1993–1999) Shortly before the 1993 election, Peters established New Zealand First. He retained his Tauranga seat in the election. Another New Zealand First candidate, Tau Henare, unseated the Labour incumbent in Northern Maori, helping to convince people that New Zealand First was not simply Peters's personal vehicle. Peters started the Winebox Inquiry in 1994; which concerned companies using the Cook Islands as a tax haven. During the 1992 and 1993 electoral reform referendums, Peters advocated the adoption of the mixed-member proportional (MMP) electoral system. In the 1996 general election, the MMP system delivered a large increase in representation for New Zealand First. Instead of the 2 seats in the previous parliament, the party won 17 seats and swept all of the Māori electorates. More importantly, it held the balance of power in Parliament. Neither National nor Labour had enough support to govern alone. Neither party could form a majority without the backing of New Zealand First, meaning Peters could effectively choose the next prime minister. It was widely expected that he would throw his support to Labour and make Labour leader Helen Clark New Zealand's first female prime minister. Peters had bitterly criticised his former National colleagues, and appeared to promise that he would not even consider a coalition with Bolger. However, after over a month of negotiations with both parties, Peters decided to enter into a coalition with National. Michael Laws, then New Zealand First's campaign manager, later claimed that Peters had already decided to enter into an agreement with National and used his negotiations with Labour simply to win more concessions from Bolger. Whatever the case, Peters exacted a high price for allowing Bolger to stay on as Prime Minister. Peters became Deputy Prime Minister and Treasurer (senior to the Minister of Finance), the latter post created especially for him. Initially, there were concerns about whether Peters would be able to