It was founded by a group of publicans and bar-owners who objected to the government's ban on smoking in bars and restaurants, introduced in December 2004.
WIN's slogan was "Freedom of Choice", and the party said that it was fighting a growing trend in which "the average Kiwi ... is being told more and more what they can and can't do".
Both van Buren and Mulvihill have been accused by the Ministry of Health of not enforcing the smoking ban, as required by law.
Mulvihill is known for supporting freedom of choice for his patrons, having once lost his liquor licence for operating around the clock prior to the legislation of 24-hour trading.
The party published the results of a survey showing that while city bars had suffered little damage from the ban on patrons choosing to smoke, suburban and rural establishments had been hard hit.