Since getting some familiarity with the Japanese Kanji system, I have the final solution to stop the boats (and all immigration in general).

Why don't we get the Abbos and the Nips together to make some impossible abbo-runes language?
Some language where each word is a scribbled letter picture thing. It has to be made specifically hard to learn (see the picture).

We could then shut up the leftists by opening the borders completely to anyone who is fluent in abborunes (impossible to learn, so no-one comes), and it shuts the aboriginies up because they get some pretend symbolistic power.
Anyone that does go to the effort of learning abborunes will be full on Australiaboo, so they won't be so bad anyway.

What do you think?