Immigration Minister Nathan Guy is scrambling to get support for his plan to lock up potential boat people.

And the Government is attracting international attention over legislation to detain "mass arrival" groups of asylum-seekers for up to six months.

Human Rights Watch refugee programme director Bill Frelick called the Immigration Amendment Bill a scare tactic rather than a rational plan, saying Guy's belief the legislation sent a signal that queue-jumpers wouldn't be tolerated was "fundamentally flawed".

"First, there is no queue. And second, the legislation does punish people who might indeed have genuine claims for refugee status."

A select committee finished considering the bill in August, but Guy is still trying to get enough votes to avoid it being thrown out at its second reading. Labour and the Greens say it breaches human rights and is unnecessary because boat people are unlikely to ever get here given New Zealand is surrounded by treacherous waters.

United Future leader Peter Dunne has called the plans inhumane and said he would need a "mountain of persuasion" to change his mind. That leaves Guy courting the Maori Party and NZ First, with the Maori Party still discussing the issue, and NZ First leader Winston Peters refusing to give any assurances.

But Guy remains confident he'll get the numbers despite Peters, Dunne and Maori Party co-leaders Pita Sharples and Tariana Turia being bombarded with more than 1500 emails since August as part of an Amnesty International campaign urging them not to back the bill.

A celebrity video last month, featuring singer Dave Dobbyn, comedian Jeremy Elwood, and actor Oscar Kightley, called on the Government to dump the bill because New Zealand was "better than that".

Meanwhile, a paper written by the Refugee Council and to be published in next month's Journal of Psychology, laments refugee issues being politicised in New Zealand for the first time. It cites evidence that detention damages asylum-seekers and "equally brutalises the people and the societies carrying it out".

The paper says the number of asylum-seekers coming to New Zealand fell from 580 in 2004 to 319 in 2009, mainly because of improved pre-flight screening.

Most asylum-seekers go into the community while their applications are processed, and the Government can already arrest anyone considered high-risk and hold them for 28 days.

Instead of locking up a mass arrival, the paper urges the Government to adopt a more humane policy - assisted voluntary return, already used in Scandinavia and Hong Kong, which saves the taxpayer money by giving failed asylum-seekers one-way tickets home.

- © Fairfax NZ News