Simon Bridges wouldn't deport mosque shooter Brenton Tarrant if found guilty despite calling for reciprocal policy

National leader Simon Bridges can't see any good reason not to deport Australians convicted of serious crimes in New Zealand, but says the alleged Christchurch shooter should serve time in Aotearoa if he is found guilty.

Earlier this week, Bridges said that if National is elected on September 19, his Government would explore a law where people could have their visas cancelled on character grounds. 

This would be similar to amendments made to Australia's Migration Act in 2014 which has led to Kiwis convicted of crime across the Tasman being sent back to New Zealand. That policy was infamously called "corrosive" to Australia-New Zealand relations by Prime Minister Jacinda Ardern, something Bridges doesn't agree with.

More than 1500 Kiwis have been deported back to New Zealand since the Australian law was enacted, with Bridges saying some hadn't been in Aotearoa for decades. 

He told The AM Show on Wednesday he doesn't "see a good reason not to do what they [are doing]".

"We are great mates as countries, that's not going to change but fair is fair," Bridges said.

"They do it to us. They are not going to change their position. It doesn't matter what Jacinda Ardern or me for that matter says to Scott Morrison or the Labor guys over there, they're not going to change.

"We should look at our interests and I say for hardworking Kiwis who play by the rules, this is the right thing to do."

Asked where the alleged Christchurch shooter - an Australian - should serve time if convicted of the multiple charges against him, Bridges said he should stay in New Zealand.

"Here's the thing. He was here only two years, my understanding, so he might be covered, but what Australia did in 2014 was they substantially lifted their rules.

"If you were an Aussie in New Zealand and you have been here a decade, we can never deport you, not even in that extreme case."

He said he would change that.

"[In Australia], some of the people coming our way, and causing the problems, they have been there for 30 years. Their rules are much tougher on us than the other way around, and that should change."

At her weekly post-Cabinet press conference on Monday, Ardern slammed Bridges' proposal as "naive", saying New Zealand can already deport criminals back to countries from which they hold citizenship. But with Australia, she said, it's a "matter of principle and a matter of proportion". 

In terms of proportion - Ardern said there are roughly 62,000 Australians living in New Zealand compared to around 650,000 New Zealanders living in Australia.

"My view is, if we think this policy is wrong, why would we then repeat it?

"My position is that we must do and continue to do everything we can to make the point that what Australia is doing is wrong and the best way I can continue to make that is not by replicating something that I don't agree with."

Tit-for-tat

Bridges said his policy is a "tit-for-tat", but "that's not even the reason to do it". 

"If there are some Aussie criminals here we should have substantially the same rules that they have over that side of the Tasman."

Newshub political reporter Anna Bracewell-Worrall is in Fiji, where Ardern has been meeting with local Prime Minister Frank Bainimarama and will son fly to Australia for a meeting with Morrison, who she has previously raised the deportation policy with.

Bracewell-Worrall says it's difficult for leaders to get other Prime Ministers to change their domestic policy. 

"[Ardern] is saying she doesn't want to engage in tit-for-tat politics. It is a bit of a tricky issue as it is an internal issue for Australia and really it is about what the Australian public wants to see from their Government."

"It can be very difficult for an outside leader to jet in and essentially convince a different Government to change a policy."

The Australian policy has been blamed for a rise of organised crime in New Zealand, with many deported from Australia being gang members. They are often referred to as 501s, referencing the specific section of the Australian Migration Act which allows for the deportation on not good character grounds. 

Following a series of violent incidents in Tauranga earlier this month, the city's mayor Tenby Powell told Newshub that there was a correlation between a spike in violence and the arrivals of the so-called 501s. 

"Things have changed. Not just here in Tauranga but in New Zealand.  With the 501 deportees coming out of Australia, the level of sophistication they bring, the level of violence they bring, and the frequency of which we're seeing it."