Australia's return to offshore processing of asylum seekers could "lift the level of risk" and send some of them New Zealand's way, according to Immigration Minister Nathan Guy.
No asylum seeker boats have ever reached New Zealand, but Guy has told TVNZ's Q+A programme "the risk is real" and law needs to be changed.
The controversial Immigration Amendment Bill, likely to be passed by Parliament, will allow mass arrivals of asylum-seekers - that's 10 or more - to be detained for up to six months.
Guy said the Government has had intelligence "over the last decade or so" that six asylum seeker vessels had indicated they wanted to come to New Zealand.
"They were stopped by other foreign authorities. We know in recent times that a steel-hulled vessel went all the way from Indonesia across to Canada. That was about 18,000km. We're about 12,000km, so in essence the risk is real," he said.
"You'll also be aware that Australia just in the last sort of month or so have gone to offshore processing up in Papua New Guinea and Nauru, and, of course, we don't know as a result of that - what that may mean for New Zealand. Indeed, it could lift the level of risk."
As a result of Australia's offshore processing, asylum seekers in boats could "look down into New Zealand and think, 'Well, actually, New Zealand's not that far away. We could get on a steel-hulled vessel, pay a bit more money and make it to New Zealand'," Guy said.
He said the Government wants to send a very strong message "that we want to detain and also dissuade those that potentially want to come to New Zealand in a large vessel.
"Also we want to have some legislation where we can manage [an] arrival if indeed it does come in the future."
The Government wants to be prepared to handle the arrival of a boat of 500 people.
The size and danger of the Tasman Sea "will be a very strong deterrent" and another will be the legislation when it's passed, he said.
Guy said New Zealand receives 750 refugees "plus or minus 10%" a year under the UNHCR process, which is working well.
"And we look over the Tasman into Australia, we see the problems that they have, so we want to send a very strong message that we have the appropriate channels open, but we don't want to be seen as a soft touch."
The number of asylum seekers is "relatively stable" at around
300 a year and only a quarter to a third get accepted, Guy
Entertainers such as Michele A'Court, Dave Dobbyn and Oscar Kightley have spoken out against the bill, taking to YouTube this week.
"I hate it when they try and make someone else's pain political," Kightley says in the video clip.