MANUS ISLAND DETENTION CENTRE WILL MEET DEMAND

Immigration Minister Tony Burke has rejected doubts over the ability of detention facilities on Manus Island to cope with an influx of asylum seekers.

The Opposition has warned the Manus Island processing centre is over-capacity just a week into the Government's so-called Papua New Guinea solution.

Under the policy, anyone arriving in Australia by boat without a visa and found to be a genuine refugee will be resettled in PNG.

Mr Burke says detainees held on Manus prior to the new policy have been moved, creating significant immediate capacity to receive people from Christmas Island.

He says offshore processing on Manus will meet demand, regardless of numbers, as "very rapid expansion" is possible.

"Nobody should be in any doubt of this simple fact: the capacity is there for us to make sure as many people [who] test our resolve will be sent to Papua New Guinea for processing their claims against the convention (UN refugee convention)," he said on Saturday.

"Also be in no doubt that people are on the ground to expand the existing capacity.

"We have members of the Army who will be there doing various forms of survey work, preparing particular sites, and we've engaged a logistics company, which has been involved in the construction of mining camps, to be able to do very rapid expansion of that site.

"So nobody should be in any doubt - if people want to test our resolve, and we always said they would try, if people want to test our resolve then whatever capacity is required will be provided, and the new arrangement will be implemented."

Coalition says PNG solution unsustainable

But Coalition immigration spokesman Scott Morrison says the number of arrivals in the first week of the policy proves the PNG solution is unsustainable.

"We've had now more than 1,000 people who are now subject to this arrangement with Papua New Guinea and that's more than twice the capacity of the Manus Island processing facility, so this arrangement is already being severely tested," he said.

"The minister was unable to give any detail today on how many beds they're creating, at what rate they can do them, at what cost, on how many additional sites that are available, how many additional landowners that had to be involved to create access to those sites.

"These remain the very serious logistical challenges that are present on creating that capacity on Manus Island in particular.

"So, the opportunity was there for the minister today to provide that detail to the Australian people... but what we had was more big, bold claims and absolutely no detail as to what was going to be delivered."

Refugee rallies held around Australia

Thousands of people in major cities rallied on Saturday against the so-called PNG solution.

Protesters in cities including Brisbane, Melbourne, Adelaide and Perth and Canberra have criticised the Government for processing and resettling asylum seekers offshore.

In Brisbane's King George Square, Philma Kelegai, a founder of a group that helps empower women in PNG, addressed the crowd.

She says sending asylum seekers to a country where 55 per cent of women have been raped, and two in three are victims of domestic violence is madness.

She says many female refugees are already fleeing gender-based violence in war-torn countries.

"Papua New Guinean women seek refuge in Australia because of these issues that are happening in PNG," she told the rally.

"We have refugees in here, how can we move women who are experiencing these types of situations into a place that is well known and documented for the same kind [abuse]?

"How do we expect these women to live there if our own women cannot survive?"

In Melbourne, Greens MP Adam Bandt called for a more compassionate approach to refugees.

The Federal member for Melbourne says Australia should work on providing safer pathways for people fleeing war and persecution to seek refuge.

"There is a country on the other side of the world where we are saying the situation is so bad that we as Australia will send our troops over there and put them in harms way, and yet, when people flee that same terror we close our doors to them. That is not the Australian way," he told the rally.

In Canberra, about 400 people turned up to protest the asylum policy outside ACT Labor's annual conference.

ABC