New Zealand's Prime Minister Jacinda Ardern has called an election for September 19, a contest that will test her popularity which soared after her response to a terror attack last year but has since taken a hit due to economic issues.

Key points: The election in New Zealand has been called early, allowing for a 235-day campaign

The election in New Zealand has been called early, allowing for a 235-day campaign Prime Minister Jacinda Ardern has called for New Zealanders to back her party for the sake of stability

Prime Minister Jacinda Ardern has called for New Zealanders to back her party for the sake of stability The election will also see the country vote in referendums on the legalisation of cannabis and euthanasia

Ms Ardern's centre-left Labour Party-led coalition came to power in 2017, and is seeking a second term.

The election was due by November this year and Ms Ardern called on New Zealanders to back her stable government.

"I will be asking New Zealanders to continue to support my leadership and the current direction of the government, which is grounded in stability, a strong economy and progress on the long-term challenges facing New Zealand," Ms Ardern said.

Earlier in January, Ms Ardern said her party would wage a "relentlessly positive" 2020 election campaign again, announcing her party had signed up to Facebook's advertising transparency tool to fight misinformation.

But her government has grappled with issues including housing affordability, urban poverty, immigration, jobs and economic growth, which are all expected to be key election topics.

Two opinion polls in October 2019 showed support for Ms Ardern's ruling coalition at its lowest since 2017, and her own popularity waning within New Zealand.

The government announced infrastructure projects worth NZ$12 billion ($11.6 billion) in December, boosting capital spending to its highest in 20 years, as it seeks to fire up the economy.

Jacinda Ardern became NZ Prime Minister in 2017. ( AP )

"We will be asking for a further term to get the job done," Ms Ardern said in a wide-ranging press conference.

The press conference also discussed New Zealand's response to the coronavirus outbreak in China, where Ms Ardern received but ignored a phone call from Australian Prime Minister Scott Morrison.

Opposition calls out Ardern Government

Opposition Leader Simon Bridges will be looking to make Ms Ardern's coalition the first one-term New Zealand government in over 40 years, and is looking forward to what will be a 235-day campaign

"Bring it on," Mr Bridges said in a statement, saying that while Ms Ardern and her Labour Party had promised much, they had delivered little.

"New Zealanders know we will get things done, whether it's more money in your pocket, a stronger economy, less tax, building infrastructure and roads or keeping families safer from increasing gang violence."

It is expected to be a challenge for Mr Bridges to topple Ms Ardern, but New Zealand's mixed member proportional (MMP) system allows for surprising results.

In 2017, the then-prime minister Bill English was all smiles on election night, declaring victory after the National Party won over 44 per cent of the vote to be clearly the biggest party in Parliament.

However, Ms Ardern, who had become Labour leader just seven weeks earlier became Prime Minister after winning over minority parties in negotiations to form government.

Without a landslide result, New Zealand's major parties are likely to rely on minority parties to govern once more.

NZ First, led by Deputy Prime Minister Winston Peters, and the Green Party independent costing.

"It's incumbent on us to deliver the campaign New Zealanders expect and deserve," Ms Ardern said.

New Zealanders will also vote on two hot-button social issues — the legalisation of euthanasia and cannabis — in referendums timed to coincide with the general election.



ABC/Wires