Is it controlling to ask someone to stop drinking entirely?

I think you've got your double negatives in a muddle there.

OP, if, as it seems, you're saying, "stop this unacceptable behaviour or the relationship is over" then YANBU.

The wider context is what's critical here (provided in later posts).
He sounds like an alcoholic.
As their parent, you have to prioritize their safety.
It is not unreasonable for you to expect your partner to be able to abide by the law (designed to keep people safe) and urinate within the designated area's at home (AKA the toilet).
The bar is really low if that's unreasonable.

He loves alcohol more than anyone or anything. More than he loves you, your children and his job. Let that sink in because thats the hard part to understand.

You need to go to every agency and anyone that can offer you help and support that you can. You need to get away from him as soon as reasonably possible because only then will he believe that you mean to take a stand but more importantly your children have to be more important to you than he is.

None of us have any idea how this will play out. perhaps when you leave it will be the wake up call he needs, he will stop and you can re examine your relationship. but perhaps he will just carry on drinking until he gets done for drink driving or done by his employer.

Personally, I would talk to the police, give them his car reg number and tell them you know he drinks and drives. he needs to start getting stopped a few times and breatherlysed because he needs to be taken off of the road.

You cannot fix him. you cannot make him stop. you cannot make this right. You are powerless in relation to him and what he does. what you can fix and control is your response to it. so put your energies into dealing with yourself and your children and ignore him. if he lives with you go and see a solicitor start the process now. save your energy for the people that matter - you and your children.

The problem with alcoholism is that even if you stop drinking, for however long you have stopped, the disease keeps progressing. This means that when you start up again it's even worse than when you stopped.

He will currently be making bargains with himself about moderate drinking and only having X amount and stopping in order to persuade himself that he can carry on drinking like a 'normal' person, but the disease will be there in the background, waiting to claim him and do URS worst.

You've done all the right things so far to keep your kids as safe as you can, but staying with him doesn't protect them 100%. You can't control everything and it only takes one time he gets behind tgdwheel with them for disaster to happen, as you know.

You have to leave. It might be the one thing that saves him..

If DH drinks too much now, he'll drink too much in the future, maybe way too much by then.
Depending on his personality and sense of awareness, he might be open to being mindful of cutting back, but if he's decided you're being controlling, rather than caring about him and his health and safety, then the only way to please you both is to cut off the relationship. Drinking too much doesn't heal itself easily, not even when the person doing it is trying to do it for themselves.

I would be telling him to leave in your position.
Of course it is okay to ask them to stop, when it impacts your life directly.
He has passed the point of any reconciliation.

This

Would he get it, being an alcoholic who drives drunk with them in the car?

Why would he fight for custody when he's not able to get sober? To avoid paying maintenance? To spite you? To "prove" he doesn't habe a problem? It surely isn't because he thinks it's in the children's best interests.

It might blow his life up - I volunteer with homeless people and a lot of them are homeless because of their alcoholism. But it's not your fault. You can't stop him drinking and if that's the path he's on, nobody can steer him off it apart from himself. You have to protect yourself and your kids - that's your primary concern now. Best of luck with it.

This is 100% exactly the same as my husband. I let him get away with far too much-including everything u have listed. He has even denied alot of it despite showing him proof (he def was hiding other things, but I made peace with it and stopped looking)
It eventually tore our family apart and we separated last year and i filed for divorce when I found out he met a new woman... in the pub he now spends all his time in. He NEEDS to do something about it now, he is putting his children's life in danger-not to mention his own and im sure u dont want to be his baby sitter? Trust me u will resent him if he doesnt get help

Sadly his drinking will never stop until either he dies or he reaches rock bottom- please don't let rock bottom be the death or serious injury of one of your children.

And you are still with him because....???

Wtf

Another frustration is the assumption that when a woman calls the relevant services they will immediately help her to leave, when it’s actually months of paperwork and letters and begging and scary repercussions so that in itself can wear someone down. With one of my family members it took twenty repeated attempts to get help for the family in place. It’s an endurance test if the woman has no where else she can go.
So practically it sounds like you’ve been doing the right things, building the case etc and obviously he’s been in a quiet phase but he’s started up again, so now you are braced for the next steps.
Are there some practical things you can do today?

Your husband drove under the influence with your children in the car? And also passed out drunk whilst caring for the children?
and he’s still your husband?

get your ducks in order and get the fuck out of that marriage before he kills someone.

This is 100% exactly the same as my husband. I let him get away with far too much-including everything u have listed. He has even denied alot of it despite showing him proof (he def was hiding other things, but I made peace with it and stopped looking)
It eventually tore our family apart and we separated last year and i filed for divorce when I found out he met a new woman... in the pub he now spends all his time in. He NEEDS to do something about it now, he is putting his children's life in danger-not to mention his own and im sure u dont want to be his baby sitter? Trust me u will resent him if he doesnt get help

You can ask them but they won't stop - not if they've got a drinking problem, and not if they don't think they've got a drinking problem - so it's pointless. Nobody can make anyone else stop drinking. If you're struggling then you can reach out to Al-Anon for help on living with an alcoholic spouse.

Splitting is going to blow up his life as well as mine and the children’s. In order to stop dangerous access I will need to involve the police again. He was violent during his last relapse. He will be arrested, bailed, and unable to come home. I will probably get a restraining order, and I will need to pray that the courts agree to only supervised access. If that’s granted for our child, it likely will be for his older children too which will limit how much he can see any of them.

Horrible as this all is, it is the road you have to go down.
You know this.
You have to do it.

Start now, put one foot in front of the other and keep going.
Keep going until you have the DC in your own home, with either supervised access only, or they age out of needing formal access (in their late teens).

You can do this. You have more strength than you can possible imagine.

Also, go to Al-Anon regularly.

What did the police do when you reported him?

This 100%. My ex only got sober when I left. I believe he would never have recovered if I’d stayed.

You need to start gathering as much evidence as you can. Without it there is a real risk that he will be allowed custody as they can't act just on your say so alone although they should take what you've got to say very seriously.
Call the police anytime you think he is drink driving. They can breathalyse him and, also important, get him off the road.
Call his work and tip them off. If he is handling heavy machinery they should also be in a position to do random breath testing.
Make sure you have access to bank records etc which show his spending on alcohol.
Keep texts, emails etc which back up what you know about his behaviour.
I know none of this sounds very nice but at this point, I would prioritise the safety of your children.

So he is an alcoholic and a dangerous one at that. I am afraid I and likely most other women would have ended this relationship as soon as it became clear he was placing your children at risk. Unforgivable, reprehensible behavior. I am not saying this to shame you but to help you see things with perspective.
Given the scale of his problem I would suggest he is highly unlikely to respond to any type of conversation or ultimatum. You will therefore need to take steps to safeguard your children, ending the relationship is the only viable option. Please check out the Al- anon website for information for families of alcoholics. Above all remember you did not cause this, you cannot control it and you cannot fix it (him).

It’s controlling if you keep insisting.
You can ask, and they can say no.

And then you need to decide what you do next.