Former airline boss Christopher Luxon was elected leader of New Zealand's main opposition National Party Tuesday, becoming the party's fifth leader to try to unseat Prime Minister Jacinda Ardern.

Luxon, who was chief executive at Air New Zealand from 2012-19, won a party room vote uncontested after his main rival Simon Bridges withdrew from the contest.

The 51-year-old is a first-term lawmaker who won his Auckland-based seat of Botany at last year's election.

Luxon said New Zealand was "heading in the wrong direction" under Ardern, whose personal popularity remains high in the electorate.

"I came to politics because I know how to solve problems and get things done," he said.

Luxon, who was chief executive at Air New Zealand from 2013-19, won a party room vote uncontested
Luxon, who was chief executive at Air New Zealand from 2013-19, won a party room vote uncontested AFP / Saeed KHAN

"I have built a career out of reversing the fortunes of under-performing companies and I'll bring that real-world experience to this role."

He is the fourth National leader in the past two years, replacing Judith Collins, who was ousted last week over her abrasive leadership style.

In appointing an experienced business executive, National hope to repeat the success of former leader John Key, a former Merrill Lynch broker who won three elections for the party and served as prime minister from 2008-16.

National produced its worst-ever result at last year's election and Ardern's Labour Party retains a lead in opinion polls.

Labour and its coalition partners are currently sitting on about 56 percent, with National and its allies just over 40 percent.

Ardern's rating as preferred prime minister is almost 42 percent, down on the 60-percent highs recorded near the last election, but still 30 points higher than her closest rival.