For a detailed discussion of the political dimensions, here is a good article to start with. For now I'm just going to point out the most basic practical problems with the proposal.
In a recent interview for Australian television, Europol director and former British intelligence analyst Rob Wainright responded to this exact question as follows:
Well, it's different to compare both. I mean, I think the two
situations are uniquely different.
First of all, think of the scale. Approximately 1.2 million people
sought asylum in Europe last year and just under 300,000 of them were
granted that. That's a figure something like 10 times what it is for
Australia in the last couple of years. So I think the scale is
According to the BBC, Australia's illegal maritime arrivals peaked at 18,000 per year. So indeed, the scale of the problem in Europe (however you may frame it) is vastly different.
Wainright goes on to raise a related point.
But you know, where in Europe are we going to sort of tow our boats back to a safe port in Indonesia? Where is the offshore detention centres in Europe we can take our refugees to?
The infamous detention center at Lampedusa is frequently filled beyond capacity. Many more such centers would have to be built if asylum seekers are to be kept there even longer then they are now.