National has disclosed allegations of violence and intimidation threatening to disrupt their election campaign.

Allegations claim a gang threat has forced a candidate to move house, a volunteer's faced death threats, and another's been the victim of a dog attack.

Labour's Angela Roberts has reported being slapped at a debate, and Te Pati Maori's Hana Maipi-Clarke says she's had a politically-motivated home invasion.

National Campaign Chair Chris Bishop says the gangs are campaigning for a third Labour term and aim to keep National out of Government.

"The behaviour our candidates have experienced on the campaign trail has been disgraceful. There's been death threats, there's been people having to move house, one of our candidates has had a Head Hunters member threaten them when they're out at dinner."

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