For those who are not aware, there is a loophole in Australian employment laws large enough to drive anything through.
If you are working through an employment agency on a casual basis you can be fired from a job without being fired. That is to say, suppose that you have been working for some period of time at one particular place and for some reason, (it can be racial, personal, sexual, religious or any other reason you can think of) the boss/supervisor there has only to ring the employment agency and tell them that you are no longer required. That's it, no explanation, no reason, no excuse. Simply tell the employment agency that you are no longer needed. Effectively fired, but because you are still on the employment agency's books you have not been fired. If they can't find any other work for you, it is just bad luck, you still haven't been fired. All of this means that you have absolutely no recourse and no ability to do anything about it under Australian employment laws, no matter what you have heard or suspect that the problem may be. The people you have been working for can say quite openly that it was racial, personal, sexual, religious or just plain vindictive but because you are still on the employment agency's books you have not been fired so therefore you can't bring any action of any kind.
Don't bother going to government departments, political parties or unions because no one wants to know. It is a nice little loophole that lets everyone off the hook, just plain bad luck for the little guy at the bottom of the heap.