So it's not OPs responsibility where he goes if he has nowhere to live, but it's DPs responsibility to provide for his family, the same DP most people in this thread are advising to kick out.
So according to the harpies of Mumsnet, he's only useful of he's bringing in money.
Let's look at the reality of this situation.
He's a 20 year old kid. I don't care about the fact that he's legally an adult. Most 20 year olds can't even do their own laundry let alone, run a household - alone, might I add.
I second an earlier response. Since you both seem to dislike the idea of working.
Both of you should actively seek work, and he first person that gets a job, which doesn't require killing yourself, should take it.
But that would require openness, and transparency which I know is absent from your relationship.
Wish you all the best. You should both get qualifications and BOTH be responsible for looking after the household, financially and environmentally.
Saying he has till X time, just makes you out to be a cold hearted bitch tbh. Thanks ultimatum I would've thought was only reserved for the likes of Job Centre advisors.