Immigrants: ah but what about the self-employed?

It's been pointed out to me that 'migrants undercut self-employed people's' rates and fees.

i've replied like this:

I agree that self-employment is a different category - I should know, I'm a self-employed person. The problem with it though is that it's largely outside legislation and that's how a lot of the self-employed like it. Everything about it is 'voluntary' our stamps, our fees, our ability to fix those fees, how we are paid...etc. We all know of self-employed people who get paid under the table (it's not just Sam Allardyce). There is no way of addressing the problem of 'undercutting' without bringing self-employment under rigorous legal control. The problem is that many self-employed people would run screaming to the press about that, saying that the only way they can survive is getting paid on a wink and a nod, and don't we 'all' benefit from cheap building work, home help, gardening etc etc? So, the fault again, is not with migrants but about the whole non-legality of the self-employed sector.