Spokesman says policy is a response to a string of incidents in recent years
A hardline law and order policy by NZ First would offer greater protection to homeowners, farmers and shop keepers who shoot to kill intruders during home invasions or burglaries.
Along with a 40-year mandatory non-parole sentence for premeditated murder, NZ First wants the Crimes Act amended to give certainty over the use of "reasonable force" for self-defence.
Ahead of the party's annual convention this weekend, law and order spokesman Richard Prosser said the policy was a response to a string of incidents that had seen farmers and shopkeepers in court over their use of firearms or even hockey sticks against would-be robbers.
Mr Prosser said so-called "castle doctrine" laws in some US states, which saw Texan Joe Horn acquitted after his 2007 fatal shooting of two men who had burgled his neighbour's home, were "so over the top that it wouldn't be something that I think anyone in New Zealand would give consideration to".
"But what I do think people have a desire for is the ability to actually defend themselves and their families in their own homes."
Mr Prosser wants a regime based on that introduced in Ireland in 2011 following controversy over the 2004 shooting of an Irish traveller by a farmer.
NZ First's proposal would allow for homeowners to use "any firearm that is lawfully available to that person" to defend themselves.
But it wouldn't provide legal justification for people to obtain and keep a gun for self-defence.
Mr Prosser said his proposed law would not allow dairy owners, for example, to keep a shotgun under the counter.
Northland farmer Paul McIntyre was tried and eventually acquitted of charges stemming from his 2002 shooting of one of three men trying to steal his farm bike.
He said current laws already provided legal protection in cases like his own.
"It just depends on how good your defence in court is."
However, if the law moved too far in giving legal protection to use deadly force, "people are going to go out and start attacking their neighbours, aren't they?
"It's going to open up a whole new can of worms."
NZ First Leader Winston Peters said that although people such as Mr McIntyre hadn't been convicted for using firearms to protect themselves or their property, "what they got was a massive legal bill for trying to defend their rights and I think that is appalling".