This election presents the clearest divide on immigration policy between the two major parties in recent history.
Labour is sticking with its promise to slash net immigration numbers by about 20 to 30,000, partly by reducing the number of international students studying low-level courses. Winston Peters wants an even bigger drop, to a net number of 10,000.
With net migration numbers at record levels the National Government announced its own tightening of immigration rules, but softened the changes after strong push-back from businesses and industry groups who said they couldn't find Kiwis to fill certain jobs.
New Zealand's population grew by 100,400 in the year to June. Net migration of 72,300 people contributed to this increase.
Labour leader Jacinda Ardern has confirmed she remains committed to their policy, likely to reduce net migration by 20,000 to 30,000 a year. The party says that will be achieved by cutting student visas for tertiary courses considered to be "low value" and susceptible to being used as a back door for immigration.
The party says it will also introduce a stricter labour market test, to ensure employers properly seek to hire Kiwis before recruiting from overseas, and require skilled migrants to stay and work in the region their visa was issued for.
Labour argues it is time to take "a breather" on immigration to allow the country to play catch-up on infrastructure, including roading and housing, and stop wages being kept low.
National has accused Labour of endangering the export education industry, and Business NZ said while the policy could help channel skilled migrants to the regions, it could mean businesses in sectors such as hospitality and horticulture struggled to find workers.
The strong push-back against National's changes - derided as tinkering by Labour - show cutting numbers is highly controversial.
The Government's original plan was for migrants to be counted as "skilled" only if the job they were coming to paid more than about $49,000 a year. That drew a backlash from dairy farmers, the horticulture and restaurant industries that said they would be put at risk if the foreign workers they relied on to fill jobs were blocked.
In a back-down, immigrants now only need to be paid over $41,859 a year - meaning about 6000 more workers can stay in the country longer. Those earning less will be considered low-skilled and can stay in the country for a maximum of three years, after which there will be a stand-down period before they can apply to come back.
Other changes included making partners and children of lower-skilled workers meet visa conditions in their own right, and temporarily closing the parent category to new applicants - a scheme that reunites thousands of migrants with their parents.
Points-towards-residency rules have also been toughened to raise the skill level of foreign workers.
The residency requirements for superannuation would also be raised under National, from 10 years to 20 years, when legislation National plans to introduce next year passes. The Government has also increased points for immigrants who have job offers in the regions.
Immigration Minister Michael Woodhouse said it was important not to "choke off" the number of people to fill the thousands of new jobs being created by a growing economy and a "balanced and pragmatic" approach was needed.
The Government has pointed to more Kiwis staying here or returning from Australia as a major factor in the record arrival numbers. Prime Minister Bill English has also frequently spoken about how many businesses struggle to hire Kiwis, because they don't turn up or fail drug tests.
NZ First leader Winston Peters has vowed to drastically reduce net immigration well below what Labour wants, to a net migration level of around 10,000 a year. Unemployed Kiwis will be trained up to take jobs as the tap is turned down, Peters says, and the number of older immigrants limited, with more bonded to the regions.
His message to voters who want a big drop in immigration levels is that Labour can't be trusted, given they had only recently called for sizeable cuts, and National will continue the "economic treason" of "mass immigration".
The Green Party had proposed capping migration at 1 per cent of population growth, but later abandoned that policy, with leader James Shaw apologising for focusing on numbers, saying he was "mortified" at accusations by migrant groups that the Greens had pandered to anti-immigrant rhetoric.
Act and United Future have both criticised proposals to cut immigration as reactionary. The Opportunities Party (TOP) wants to overhaul the system so immigration isn't driven by student visas or reciprocal visitor working visas, and scrap the need for highly-skilled migrants to have a job to come to.
National last year announced that New Zealand's annual refugee quota would rise from 750 to 1000 in 2018 - the first increase since the quota was established in 1976.
The Greens want the quota increased to 4000 within six years, with an additional 1000 taken by NGOs. Labour wants the quota to hit 1500 over three years.