ACT and National are condemning threats and violence against political candidates as "unacceptable" and "disgraceful".
National says its candidates and volunteers have often been facing threats from gang members, while ACT says such concerns should be dealt with quietly by police rather than in public.
Based on recent polls, the two parties are on track to being able to form a government after the election - though they may also need NZ First. It is something National's leader Christopher Luxon has consistently said is not his preference but what he would be willing to do to keep Labour, the Greens and Te Pāti Māori out of office.
The other parties in Parliament - Labour, the Greens and Te Pāti Māori, have in the past week been warning about increased levels of violence and vitriol on the campaign trail.
Te Pāti Māori's fourth-ranked Hana-Rāwhiti Maipi-Clarke's home was invaded, vandalised, and had a threatening letter left behind in what the Hauraki-Waikato candidate said was a premeditated, targeted and politically motivated attack.
Labour's Taranaki-King Country candidate Angela Roberts was also slapped, and the party's Northland candidate Willow-Jean Prime said she had faced more anti-Māori comments at events than ever before. She has contested every election since 2014.
Labour leader Chris Hipkins on Thursday gave a speech promising to call out race-baiting and explicitly criticising National, ACT and NZ First for their rhetoric, saying it was playing on people's fears and would chip away at the Treaty of Waitangi's place in New Zealand.
National's leader Christopher Luxon said National condemned any threats and violence against political candidates.
"We condemn any threats and intimidation on any political candidate, their family or their property. We live in a democracy, it's a tremendous privilege to have it," he said.
"We have been the recipients of abuse ourselves, and our own candidates and our own volunteers. Just this morning we had [a volunteer] out campaigning that had wood thrown at them and we've had some serious incidents that we've raised with the police."
"I have spoken to the individuals concerned because some of them are quite concerning and have put them at physical risk and they have understandably been quite shaken by it."
'Pretty full on' gang threats - National Party
National's campaign chairperson Chris Bishop said in a media statement he was "taking the unprecedented step of publicly sharing information about incidents of violence and intimidation during the election campaign".
"We are reluctant to speak publicly about these incidents. Our priority is on New Zealanders and the critical issues at stake in the election ... criminal gangs like the Mongrel Mob have publicly endorsed the Labour Party and this has put National's candidates and supporters at heightened risk," the statement said.
He listed examples of incidents including a candidate being forced to move house after a gang threat, death threats made to a volunteer in Auckland, an "allegedly intentional dog attack on a door knocking volunteer, resulting in injuries worthy of medical attention", volunteers being abused and followed by gang members in Hawke's Bay, and a candidate having beer thrown over them with their volunteers intimidated and house broken into.
National's Auckland Central candidate Mahesh Muralidhar said he was filmed in a restaurant without his knowledge while wearing his National Party jacket.
The video has now been shared online with a gang boss narrating over the top.
Muralidhar told Checkpoint candidates and volunteers should feel safe campaigning.
He has not changed the security around his campaign effort but has asked his team to be more mindful, saying their safety was the most important thing.
Luxon also said much of the threats and intimidation for National had come from the gangs.
"They have been pretty full on to be honest, with many of our candidates and our volunteers out and about ... that is incredibly worrying and concerning.
"Our people shouldn't be intimidated because of gangs getting involved in the political process and threatening our people."
Bishop earlier told Morning Report candidates, volunteers and MPs had been subjected to "awful abuse and intimidation" from gang members.
"I've had reports just in the last 48 hours or so of a senior headhunters member filming one of our candidates at a bar and posting it online with derogatory comments and intimidation ... a couple of our candidates around the country have had gang members say to them look, this is a Labour town and they need to get out of town."
He said the Labour Party was "being supported by gangs around the country, Harry Tam and the Mongrel Mob ... encouraging gang members to go out and vote for the Labour Party".
Tam, a Mongrel Mob life member, said he thought Bishop's argument was "a bit bizarre".
"[Bishop]'s been trolling my page, my Facebook page, for some time now and making up TikTok videos of me and all sorts of things, and I think that's intimidating in itself.
"All I'm doing is basically encouraging our people to exercise their democratic right and I would have thought that Chris [Bishop] would have been supportive of that given that we do live in a democracy."
He said he was had been encouraging members to vote in some cases for the Greens or Te Pāti Māori, not just Labour, and he had not been hearing any cases of gang members intimidating political candidates.
"I don't know every gang member in the country, but certainly the people that I talk with it's the last thing on our minds, our people are just struggling to survive let alone intimidating politicians.
"I don't know of any of our people've been involved in intimidation, in fact I checked with the police today and they don't know of anything so I guess the thing is if this is happening, Chris knows what to do and that's to report it to the police."
He said National was trying to scare voters away from Labour by associating the party with gangs.
"Like, the electoral commission is promoting enrolling people to vote and that's all I'm doing, is doing the work of the electoral commission unpaid ... given that National's talking about saving costs, they should be praising me for saving the government costs for doing their job for them."
ACT's David Seymour told RNZ any kind of political violence was "totally un-Kiwi and unacceptable in New Zealand's democracy".
He said the party had needed to involve police over multiple threats.
"We've had people that have made quite specific threats against candidates, have threatened to disrupt events, and indeed have disrupted events and in each of those instances we've had to involve parliamentary security and police."
However, he questioned the way Maipi-Clarke had dealt with the invasion of her home.
"We actually believe that these kinds of incidents are best dealt with seriously and quietly with the potential perpetrators or actual perpetrators identified and dissuaded. We don't think it's a good idea to try and politicise such incidents such as by trying to blame other politicians for them when there is no connection - because that just will lead to an escalation.
"We just think that people need to get back to rational healthy debate on the issues rather than dogma and especially any kind of threats of violence."
He said he was not trying to diminish what happened, or cast doubt on it.
"We take her at her word that they did occur and suggest that all politicians should be collegial ... but to really play it out, and finger point in the public sphere, that only leads to further difficulty and disorder."
He acknowledged that women and Māori were being subjected to more abuse than others: "I have no doubt that, looking at the abuse that our female and Māori MPs have taken, that there is a bias in that sense and yes ACT's female MPs and Māori women MPs I feel get more and worse abuse, and I wish that was not the case."
However, when asked if political leaders had a responsibility to dampen down supporters from seizing on political rhetoric and taking it too far, Seymour said there was "no suggestion that there's any risk of that".
"There is no place for political violence in New Zealand's democracy. And you can't be a very good debater if you have to physically attack somebody. In a sense it's actually a concession of defeat of the argument, besides it being absolutely unacceptable."
Senior Labour MP Grant Robertson said the abuse candidates were experiencing this campaign was worse than previous elections.
Political parties should be able to campaign fairly and freely, he said.
"It does feel a bit worse to me, I think that's been probably an evolution over the last few years.
"There's always been tension in campaigns, there's always been defacing of billboards and so on but I think some of the things we've seen and heard in recent times indicate a higher degree of that this time."
Heightened levels of tension and abuse this election were unacceptable, Robertson said.