The partner is not paying off his debts, the tax payer is. I'm sorry, I've not read the last page, but this is where I'm up to.
She is committing fraud by pretending to live alone. How can the 3 of you be so stupid that you think this is OK?
Some of the first questions on forms is about your living arrangements. At some point she has physically written on a piece of paper that he does not exist.
It also does not matter if it's a house share with a housing association, or a private mortgage, she will still have to declare exactly their circumstances, and I honestly don't know what she could say that would make this ok.
Meanwhile, one phrase you used leapt right out at me.
She will give him the money, and he will use it as the deposit?
Given his history with money I would bet my house that the money will not end up with the solicitor, he'll say "why do we even need a house?" and he'll gradually work his way through that money as well.
If you do end up with a house, and then the fraud is discovered, it will by that stage be a prison issue, because they'll be looking at benefit fraud, mortgage fraud, and bank fraud at the least.
You do know that just because it all involves council money, and government money, it still counts, right? You still can't " just, sort of, well I thought it would be ok" about it?
Would you walk into the bank of England and expect them to overlook this shit?
I don't care WHAT she was trying to achieve, and I'm surprised I'm saying that, but this idea that the benefits office will look on you benignly like a cosy mum and dad ages me want to smack someone.