It is nonsense, of course. All the evidence points to the fact that the turn-back policy has been a hugely successful deterrent to people smuggling. People may be tempted to risk their lives, but they are not prepared to waste their money by paying a people smuggler only to be certainly turned back.

All the refugees on Manus and Nauru could be brought to Australia without any security risk or any risk of the resumption of people smuggling.

But it is not going to happen because the Coalition needs Manus and Nauru as a propaganda distraction.

Refusing to resettle the refugees on Manus and Nauru is not to send a message to people smugglers. Rather it is to send a message to a rump of disaffected white Australian voters who fear loss of cultural identity: “Look at us. We are the only party you can trust to keep the foreigners out and keep our borders safe. Please ignore the real cause of your wages stagnation and long health and education queues.”

The real cause, of course, is high population growth – put by the Australian Bureau of Statistics at 404,800 in the past year, 61 per cent of which was from net immigration. Even without any immigration the population would still grow.

Australia’s annual growth rate of 1.6 per cent is close to three times the OECD average of 0.6 per cent.

But the Coalition will do nothing about it because those immigrants provide consumers and cheap labour to its supporters who make their money turning farming land into shopping malls and housing, and turning wilderness into marginal agricultural land.

Another result emerges from the vilification of refugees. People who want more humanity shown to refugees are made to feel that they must support all people coming to this country and therefore support high immigration.

It means, for example, that any debate about population on the ABC or SBS, or most other places, for that matter, is shut down for fear of those pointing out the adverse effects of high population being branded racist.

Even the otherwise unbiased Lowy Institute slants its immigration question in its annual poll of Australian attitudes which came out this month.

Its question asks: “Thinking now about Australia’s immigration program. Do you personally think that the total number of migrants coming to Australia each year is too high, too low, or about right?”

My guess is that very few respondents would get within cooee if they were first asked to state what is the total number of immigrants coming to Australia before asked whether the number is “about right”.

Even with a bias for the easy “about right” option, 47 per cent said it was too high.

If that question were rephrased to: “Australia’s annual population growth is 400,000, 60 per cent of which is from immigration. At 1.6 per cent it is more than double that of the UK or the US, do you think . . . . “, the result would probably be very different.

Getting a sensible debate on population in Australia is very difficult.

It may be clever or it may be inadvertent, but the net effect of refugee vilification and the prisons on Manus and Nauru is that high immigration can continue to deliver wealth for the very few and votes, via One Nation to the Coalition.

Some refugees on Manus and Nauru are this month entering their seventh year of imprisonment without charge or trial. It is a crime against humanity.

There is no reason why those prisons cannot be closed and the refugees brought to Australia. Except one: their propaganda value to divert attention from high population growth.

Surely, the Government is not going to keep that vote-harvesting propaganda weapon in place for the whole of its term so that by the end of it some refugees will have been imprisoned for nine year despite having committed no crime?