Immigration has been a hot topic in recent months, with new migrants accused of contributing towards both the housing crisis and low wages.

Net migration to New Zealand surpassed 70,000 last year, with pressure now starting to be felt on infrastructure, schools and hospitals.

In January, Massey University Distinguished Professor Paul Spoonley told The Weekend Sun nearly all of New Zealand's population growth is going to occur in the top half of the North Island.

He also says since 2012, two-thirds of our population growth has come from immigration. 'And we do need to be aware that immigration is where we get our people from,” says Paul.

He uses Auckland as an example of a city that has done 'a very poor job of providing infrastructure for growth.”

The local kiwifruit sector also relies heavily on seasonal workers, of which a significant number are migrant labourers.

They can often be targets of exploitation, as a Labour Inspectorate operation found earlier this year.

Inspectors carried out audits on 62 labour contracting companies and interviewed 687 employees during the operation which occurred over three months last year, ultimately uncovering 94 breaches of minimum employment standards.

The operation showed 53 per cent of employers were failing to meet all minimum employment standards, such as providing employment agreements and paying at least the minimum wage.

'Almost all of the employers found in breach were using migrant labour, which is concerning because these are vulnerable people who may not fully know their rights and entitlements,” says Labour Inspectorate regional manager Kevin Finnegan.

The Weekend Sun asked local candidates for their thoughts on immigration and how their party would tackle the issue.

Todd Muller – National

Migrants make a valuable contribution to New Zealand and the Bay of Plenty, both culturally and economically. New Zealand's economic success is built on our openness to new ideas, our welcoming of talented individuals with skills and experience, and making sure our businesses have access to new and emerging markets. The government is committed to striking the right balance between ensuring New Zealanders are able to find jobs and ensuring our regions have access to temporary migrant labour necessary for sustained economic growth. Immigration is vital for filling labour shortages for industries such as horticulture here in the Bay. We want these industries to be able to grow, which is why employers will continue to be able to hire migrant labour if they can prove there are no New Zealanders available to do the job. Slashing immigration by ‘tens of thousands' as opposition parties propose would put our primary industries and small to medium-sized businesses under immense pressure.

Todd is standing in Bay of Plenty.

Tamati Coffey – Labour

Labour loves the idea of Kiwis working in Kiwi jobs. What we need here in the Bay is to empower Kiwis to retrain so they can meet the needs of our changing work environment, which is why Labour is offering three years free tertiary study so that our workers can get the skills needed to do our jobs and help us lower the insane amount of net immigration, which at the moment is far too high. Labour supports a strong Bay economy so we won't touch RSE as it's vital to the success of our kiwifruit industry. A vote for Labour will stop the crazy open door policy of the past nine years. What will change are some of the details in Skilled Visas to make sure that those people who are migrating here have the best chance of fitting in with their new Kiwi communities.

Tamati is standing in Waiariki.

Clayton Mitchell – NZ First

I think it's pretty obvious to everyone we can't bring in an extra 73,000 people – more than the population of Rotorua – every year, without building an extra ‘Rotorua' to cope. Rotorua has two hospitals, 12 schools, and numerous houses, businesses, and other infrastructure resources that we aren't adding along with our hyper-immigration influx. New Zealand First is pro-immigration of people we need, not people who need us. Those who can add value to our economy must of course be prepared to respect our laws, our culture, and our flag.

Low-skilled migrant workers who come here under the RSE visa scheme to pick kiwifruit come for a season and then head home afterwards. They are providing a service with clear parameters, and a clear departure date, so that seems to fit with our policies of bringing in people we need – as long as New Zealand workers and their wages are protected.

Clayton is standing in Tauranga.

Emma-Leigh Hodge – Greens

Currently there is a trend toward scapegoating immigrants, and while it may be convenient to blame our housing crisis and the like on immigration, this is lazy politics. Politicians have a duty to be bold and fix the underlying issues in our society, not just blame others for them. We know immigration, handled sustainably and in an inclusive (not assimilative) way, is good for Aotearoa. Treating immigrants respectfully, and working in partnership with local communities and tangata whenua to create a well-functioning diverse society is at the core of the Green's policy.

The Bay attracts many temporary migrant workers and the Green Party would grant these workers full labour rights to ensure adequate working conditions, fair pay, and access to essential services. As always, the Green Party is committed to regular, evidence-based reviews of the government's immigration policies to ensure these continue to meet the needs of all our communities.

Emma-Leigh is standing in Tauranga.

Stuart Pedersen – ACT

ACT welcomes immigrants but immigration should not be used to drive economic growth, as only improving productivity will make Kiwis better off.

There is no ‘right number' for immigration. What matters is to get the rules right. ACT successfully advocated that national superannuation not be paid until an immigrant has been here for 20 years. And ACT believes that all migrants should commit to a Kiwi Values statement.

The fact is, recruiting overseas is a costly, risky, last resort. So when businesses need immigrant workers, ACT will never stand in the way. Rather than bureaucrats picking sectors with shortages, ACT will look at wage data and favour sectors where pay rates are rising fast.

Ethnic and cultural diversity is great for our community. Rather than demand assimilation we should invite it by being welcoming and hospitable. The first generation may face language and cultural headwinds, so we should be patient.

Stuart is standing in Tauranga.

Rusty Kane – Independent

Immigration has played an important part in shaping New Zealand. But we are suffering from our own success. The country's population grew by 100,400 in the year to June. Net migration of 72,400 people contributed to this increase. Most migrants arrived on short-term work and student visas; many needed for the dairy, horticulture and restaurant industries. Immigration numbers also puts demands on the country's services and infrastructure and low-skilled migrants help to suppress wages. We are now past the point where the unchecked high immigration numbers have become unsustainable for the country to absorb, to a point where we need to reduce net immigration. Immigration is of little economic benefit to New Zealanders in terms of raising our standard of living, especially if it is used as an alternative to policies such as upskilling the labour force and if we do not build the infrastructure that the expanding population and economy needs.

Rusty is standing in Tauranga.