Yeah I don't disagree entirely with the intent - stop tax dodging by dodgy companies and by dodgy contractors.

But the implementation, my god, it's a mess, and it seems to put the liability all in the wrong place, on the weakest party in the relationship.

And as I said elsewhere, the root cause of the difference in taxation for the contractor is that investment income is taxed less than earned income, something I find pretty hard to accept in principle.