I am a cleaner for a very wealthy middle class family, my dh is the full-time gardener. Before we came here (live in a very nice tied cottage and let our own house out), we had our own successful landscape gardening business. We would not have come here had it not been in our favour - so whilst technically he could be called a servant by some of you we would not be here if he was treated like one.
However, I do 6 hours a week cleaning for them for cash in hand. Not once in any 3 hour stint have I been offered a cup of tea or coffee, the radio was taken out of where I do the ironing so no fun there, so yes, I feel not too far up the ranks from a servant. Also, they will go out and not say they are going, so I don't know if to wait for them or just leave, basic common courtesy to me and all ways of making me feel inferior. But, it is convenient, flexible and if the kids are sick I don't go. So, if you have a cleaner please make sure she doesn't feel like you're doing her a big favour, and the odd compliment on her work will go a long way.
Back to the point - I can't imagine a tax break would make any difference to people in this sort of class at all, its more the hastle of having to do payroll, holidays, sick pay etc. and the fact it is difficult to sack somebody if you have a change of situation. I would love to get a 'proper' job but lack of any childcare is the problem in rural areas like this, let alone affordable childcare.