Expected to care and provided for my older brother

make sure your brother is on the electoral register each a year and see if he is named on the council tax demand. This would obviously show how long he has been living in the uk after being abroad for a number of years. In the future he may need housing benefit or council tax relief and this things maybe useful to show. They may never be requested, but its worth ensuring now for peace of mind

if I was in your position and your mother was no longer with us

If your brother was not on the tenancy, id help him fill out the homeroom/council forms, check out their website to do once you are homeless.

if he is aged over 55 then its likely he will be housed much quicker, if he is homeless he will be housed much quicker, the council will be aware they have removed his home as his mother has died

all these things will help him get a place of his own

making sure he bids for properties each week, as that is often the state of "being on the list" many people don't bother to bid weekly and then will complain they've been on "the list" for 2 years and not been offered anything. Yet others who bid each week get offered a property in 4/5 months. Of course they'll be exceptions to this, bt in the majority of cases its people not doing what they need to do, either through ignorance or inability

there is usually over 55 accommodation available through the council or housing associations. So that’s what he’ll have to move in to.
You could prepare by seeing what’s available in your area and where it is advertised. If your mum can pass the house to him that would be great as then he could swap and they’ll be keen for him
to swap. I wouldn’t mention it to either of them but I would be prepared so I knew the process

His choices, his problem.
You are both adults, he has been able to hold down jobs for years and avoid paying child support. He is not vulnerable and in need of care. Your mother can choose to house him but nothing moral or legal says you have to.
You could suggest to him that he gets advice, CAB or Shelter, on his housing position now and in the future. Possibilities are that he gets added to your Mum’s tenancy and can then stay on, that he accepts he cannot have this for some reason and applies now for social housing as he will wait ages, that he does nothing now and presents as homeless when that is necessary (benefits would be assessed on new situation).
As your mother is 80 I assume he is not yet of state pension age so a possibility of course is that he gets a job and is able to support himself. And help her out. But from everything you have said that might not be attractive to him.

Well there you go then, there’s your genuine reason why he can’t ever move in.
”If he moves in I won’t be allowed to continue my job and will therefore lose it”.
He can’t move into a house that you can’t pay the bills for with no job!
I honestly despair of the emotional blackmail some families feel they have a right to heap onto the person that they decide should be looking after everyone else.
If your mother’s so worried about her leech of a son being incapable of managing, she should be helping him sort his own life out - not preparing you to have yours messed up by him too.
You need to grow thick skin and set iron clad boundaries - this is Not on you to resolve. He is not your responsibility and no one should be making you feel that he is.

Been where you are OP…

You need to be clear up front and don’t leave anything to assumptions. Start prepping your brother now to start thinking about what is going to happen to him. Even if it means he dislikes you now and you fall out… you’re going to fall out anyway when the time comes and he realizes you are not mopping up after him.

Do not let anything be vague now. Give him a fair chance to make a plan before he assumes that his future is sorted. Then your conscience is clear.

No, of course you don't need to provide a roof and care for your adult brother. Neither does your mum. He doesn't need to be able to afford to maintain a 3 bed HA flat alone. If he is made homeless when your mum dies, if he is 60+ and unable to work because of illness health he will be accommodated and wait listed for a suitable property.
If your mum is able to add him to her tenancy then he may be able to inherit that and then exchange it for something more affordable and suitable for him when the time comes.
If he is terrible at admin then you could consider helping to find out what the options and likelihood of these are now. Helping him settle independently long term rather than upending your life and comfort.

One of them can have him then.

No but if the tenancy transfers to him the council can then move him to a smaller property and they’ll lease the 3 bed to a family.

Im surprised that didn’t happen to your mum as a single woman in her own.

Mh council always move people and pay towards moving costs.

Yeah this stopped a while ago in the LA housing I used to work for. They also won’t have a legal duty to rehouse him.

Sorry, but he’s an adult. Your family should expect him to be able to conduct his life independently, not for you to take care of him.

I started reading your OP expecting you to say he was disabled or had some sort of special needs and that your mother had been his life-long carer - but he’s not, is he? He’s a selfish, self-centred fool who has been enabled in his poor decisions by your mother offering him refuge in her home. She is entitled to make that decision, however foolish it is, because she is his mother and also an adult. No one can impose that choice on you.

As other PPs make clear, he is not your responsibility when she dies. He can apply for social housing and UC etc either now or when she dies. Not your problem. I’d just make it clear now, if the conversation ever leans into it, that you are not offering money or a home to him. As the expression goes: he’s big enough and ugly enough to sort himself out.

It’s really simple, when the time comes you help him look (if asked) at rental options. Then, when it becomes apparent there are none - he declares himself homeless to the council and follows the necessary process to be rehoused.
With kindness (and you don’t even suggest this, so more aimed at your family), what about your brother makes him so special he shouldn’t follow the current processes necessary to find accommodation? Why should his stubbornness at his own situation be your problem?
If you put him up, the council will never house him. Sometimes you have to be cruel to be kind.

Just act surprised if anyone hints you might take him in and say “that’s not possible “ and “ that won’t be happening “.

If your Mum raises it say “if you are worried Mum, his best bet is to get on the tenancy here, or at least to stay here do that he can get council help if this place is deemed to big for him”

Grrr: people like your brother make me do angry, silting up the availability of social housing that should be available to young struggling families - but no way is that YOUR problem to try and solve.

Your home is your workplace. You don’t want an alcohol abusing, on the sick, ageing man who will become more frail and needy in your house all day long.

We have a similar situation with bil. We very firmly said we are not taking him in. Mil seemed surprised and tried to guilt trip DH, but he stood firm (thank god) I honestly don't know what will happen to him in the future and sometimes I do feel bad for the guy but his situation is entirely of his own making and not our responsibility

Just say no . The guys a loser through bad choices . Don’t let him move in be one of yours . If your family get upset say they’re welcome to have him move in with them .

Doesn't sound as if that should stop him working though?

This. To be honest I wouldn't duscuss it until it happens - it'll only cause you trouble sooner.
Stand firm when the time comes. Tell him to ask his NOK (DD) 😂

https://england.shelter.org.uk/housing_advice/council_housing_association/stay_in_home_when_council_tenant_dies?gad_source=1&gad_campaignid=2009265823&gbraid=0AAAAAD-7KjVvAzxfUXWHzAau2oN_9zigq&gclid=Cj0KCQiAiebIBhDmARIsAE8PGNLoE9QvSeUBbDylXiN_Yw9BWz1QEPbjZiJXrKuP2-OH98zSAtifqzMaAkmaEALw_wcB

He may well have the right to succeed to your mothers tenancy in which case he will be offered a smaller property that will be paid for by benefits

I suggest you make sure that your mother has declared he's living there

Not even a single night at yours! He’s not your responsibility. Don’t do it. Why should you? So what if family think he should be the parasite in your life? You ought not to be supporting him.

So he turns up at the council as homeless. A place in a hostel might focus his mind to get a job.

You say that your brother has earned a lot over the years living abroad; has he made any private pension arrangements? Has he paid enough NI in the UK to qualify for a state pension?

I would take a very large step away from this OP, your brother is an adult and you are not responsible for him. All those caring (judgmental) family members are free to step forward and take responsibility for him.

Most HA’s have stopped this now.
I work in housing, and the amount of men that moved in with their elderly mother in the former family home, for a few weeks/months before trying to get added to the tenancy was shocking.
It was ALWAYS men too, 9/10 in to their mums 3 bed house. Then they would want the tenancy in their name when their mum died or went in to a care home. Single men taking up family homes. Sometimes there assisted with a 1 bed flat. Sometimes they are told to find their own accommodation.

Just say No, I have similar issue with older sister, I've let my mum know in no uncertain terms that I will not be taking her and her problems on after mums death.