The party was the biggest beneficiary of New Zealand's switch to mixed member proportional representation. In the 1996 elections, New Zealand First won 17 seats. In addition, it swept all five Māori seats. Henare was reelected in Te Tai Tokerau (the former Northern Maori). He was joined by Rana Waitai in Te Puku O Te Whenua, Tuku Morgan in Te Tai Hauauru, Tuariki Delamere in Te Tai Rawhiti, and Tu Wyllie in Te Tai Tonga. The four new MPs each pushed Labour into second place. When New Zealand First entered a coalition with National with Peters as deputy prime minister, Henare and Delamere joined Peters in Cabinet. Henare served as minister of Māori affairs and Delamere as minister of immigration and Pacific affairs.
The five Māori MPs soon became known as the "Tight Five," after the five rugby forwards who do most of the pushing in a scrum. Largely because of their huge electoral upset, they gained a very high profile in both New Zealand First and nationwide. However, they along with many other New Zealand First MPs attracted some controversy for their behavior. Morgan, in particular, caught heat for reportedly misapropriating funds from a television network where he worked before entering Parliament.
When National's Jim Bolger was ousted as prime minister in a party room coup by Jenny Shipley, tensions rapidly developed between the coalition partners and within New Zealand First itself. Eventually, Henare tried to stage a party room coup of his own against Peters, but failed. Soon after that, Shipley sacked Peters from Cabinet. Peters immediately pulled New Zealand First out of the coalition, but eight New Zealand First MPs left the party instead and continued to support National as independents. Among these MPs were all of the Tight Five except Wyllie.
In the 1999 elections, all of the Tight Five were defeated, with only Delamere managing to even finish second. Henare is the only one who has remained in politics, but did not return to Parliament until 2005, as a National list MP. Waitai and Delamere have also rejoined the National Party since leaving Parliament.