- Latest poll put Labour ahead of incumbent National Party
- New Labour leader Jacinda Ardern only took over the party at the start of August
(CNN)"Bill English, why are you losing?"
That was the opening question in Thursday's New Zealand election debate, and one many supporters of the incumbent prime minister may be asking themselves as his National Party suffered its worst poll showing in 12 years.
In a development no one would have predicted only a month ago, a resurgent Labour Party has swept into first place in a new poll conducted for state broadcaster TVNZ.
The poll, released Thursday, put Labour up six points at 43%, with National at 41%.
According to CNN-affiliate Radio New Zealand, Labour's average in the three most recent polls was 39%, compared to 41.8% for National. Trends show Labour is increasing support, while National has been steadily dropping, the broadcaster reported.
New Zealanders go to the polls on Saturday, 23 September 2017. The party with a majority in the 120 seat House of Representatives forms the government, meaning only Labour and National have a realistic chance to take power without forming a coalition.
English -- who replaced former National leader John Key in December -- called the election in February, as Labour was seen to be struggling in the polls.
But, just as UK Prime Minister Theresa May was stunned by her Labour opponent, Jeremy Corbyn, who overcame the Conservatives' huge polling lead to steal their majority and force them to form a coalition with the far-right DUP, English has found a far stronger opponent than he expected.
Jacinda Ardern, a 37-year-old three-term member of parliament, was elected Labour leader on August 1. Since then, her party has surged in the polls, leading the local press to coin the term "Jacindamania."
If elected, Ardern would become New Zealand's third female prime minister, and the second-youngest, after Edward Stafford, who become Premier in 1856. He was also 37, but born later in the year.