News from earlier this month
The Australian government has turned down the UK’s offer of a post-Brexit trade agreement that included visa-free work and travel between the two countries.
Trade minister Simon Birmingham said full free movement would not be accepted because it could cause an exodus of highly trained workers to the UK and an influx of unskilled British workers to Sydney and Melbourne.
The 2nd part of that last statement seems a bit weird. At least judging from the case of EU enlargements to the east, both skilled and unskilled eastern workers migrated to western EU (and there wasn't much of migration in the opposite direction). There are actually some countries in the EU that see both processes at the same, e.g. Italy, but the destination countries to which it experience its brain drain (mainly Germany, but also the UK) are not the source countries for (most of) Italy's low skilled immigrants.
So why would unskilled (or low skilled) UK workers flood Sydney and Melbourne (if Australia gave them the chance)? In pure economic terms, there would have to be a large enough different in attraction (for unskilled labor) between substantial parts of the UK and Sydney/Melbourne (wage difference, perhaps also taking into account the cost of living, and also regional unemployment); is that the case though?
(There's an article in the Guardian that says that the cost of living in Sydney is higher than even in London. I'm not sure how that translates into [unskilled] salaries though. Housing definitely seems more expensive in Sydney than even in London, with a median price to income ratio of 12.9 vs 8.5, and even Melbourne at 9.9 has it higher than London.)