The entire Australian mainland has been excised from the migration zone in a bid to deter the arrival of asylum seekers.

Up until now, asylum seekers who reached the mainland by boat could not be sent offshore to Nauru or Papua New Guinea's Manus Island for immigration processing.

The change strips away any legal advantage for asylum seekers who reach the mainland.

The bill was supported by the Opposition, which says it is almost identical to legislation put forward by the Howard government in 2006, but the Greens predict the next generation of Australian politicians will be apologising for it.

Asylum applications by country 2012 Country Applications United States 83,430 Sweden 43,890 United Kingdom 27,410 Switzerland 25,950 Australia 15,790 Italy 15,710 New Zealand 320 Table shows selected countries, not a top list. Source: UNHCR

The idea was one of 25 recommendations put forward by the expert panel on asylum seekers and introduced to the Parliament by the Government last year.

As a matter of urgency, the Government re-ordered today's day in the Senate to ensure the bill passed.

Coalition Senator Michaelia Cash says Immigration Minister Brendan O'Connor paid a special visit to the Opposition to get the measure through the Parliament.

"The Government and the Minister O'Connor came to the Coalition quite literally on bended knee today and begged us, begged us to facilitate the passage of this legislation, which again for the record, we agreed we would do," she said.

The Government, which is dealing with an increasing number of boats arrivals, says it is a deterrence measure.

But the Greens and refugee groups say it strips asylum seekers of legal rights.

Greens amendments to allow for Human Rights Commission inspections, media access, and the removal of children from the Manus Island centre, all failed to pass.

Greens Senator Sarah Hanson-Young says the bill will do nothing to stop people arriving by boat.

"It is going to cost people's lives and damage people who are already suffering from such harm, this is a bad piece of legislation, an immoral piece of legislation," she said.

"[It is] not looking at why people are seeking asylum in the first place what is driving them to leave their countries. Deterrence has not and will not work."

Greens leader Christine Milne says after apologies to the Indigenous children of the Stolen Generation and the children of forced adoptions, the Government should be warned.

"In 10, 15, 20 years when there is a national apology to the children detained indefinitely in detention for the sole, supposed crime of seeking a better life in our country because they are running away for persecution with their families, not one of you will be able to stand up and say "Oh we didn't, oh, it was the culture of the period'," she said.

Amnesty International also says it is appalled by the decision.

"Until today, the Government's policy of removing asylum seekers from the mainland and locking them up offshore was against Australian law," Amnesty refugee campaigner Graeme McGregor said.

"Now the Government has changed the law to suit their policies. This doesn't change the fact that this is an inhumane, ineffective and expensive policy that ignores Australia's responsibilities to people who need our protection."

Human Rights Commission president Gillian Triggs says it discriminates against vulnerable people and penalises them for the way they arrive in Australia.

She warns transferring asylum seekers to a third country may breach their human rights.

All asylum seekers could soon be sent to offshore immigration processing centres. ( Roslan Rahman: AFP )

Policy backflip

It is an about face for the Labor Party, which rejected the Howard government's similar legislation in 2006.

At the time, Labor MP Chris Bowen described the proposal to excise the mainland as "a stain on our national character".

But after introducing the bill last October, Mr Bowen, who was then the immigration minister, said he had changed his position.

"I've changed the Labor Party's position and I changed my mind, based on the evidence, based on the recommendations of the Houston panel, and based on the evidence that this will save lives," Mr Bowen said at the time.

Several boats have arrived on the Australian mainland this year, including the embarrassing case of the New Zealand-bound boat of Sri Lankan nationals which arrived in the West Australian port of Geraldton.

Labor Senator Matt Thistlethwaite says laws have to change to save lives, citing the Christmas Island tragedy in December 2010.

"Fifty innocent women and children drowned in shocking circumstances before the eyes of this nation on the rocks at Christmas Island," he said.

"We simply cannot allow, as a nation with a heart, those circumstances to continue."