macnab unfortunately it sounds like I'm in exactly the same position as you. I've written letters in the past too. I empathise deeply. sigh
Knitting part of the problem is that it would be so difficult to separate things down the middle - we share a car and a house etc. If I was to give him specific tasks and they didn't get done (which they wouldn't) it would be the DCs and I who suffer.
BigChoc that could be an idea, I would just need to adjust to not stepping in which I know I would find hard. I realise that part of that is down to social expectations which I should try to pay less attention to anyway. I know though (and I've tested this) that if we had people coming over and I knew the place was a tip, toilets dirty etc he wouldn't notice or do anything about it, and being a bad host would make me feel very uncomfortable and embarrassed, regardless of whose fault it was.
He can cook but generally makes whatever he fancies eating. He tries but he's also one of those people who creates chaos when he cooks, uses every single pot and pan etc and doesn't see the mess to clean it up, so guess who ends up cleaning meat spatters off the walls - it'd be easier and less stressful for me if he didn't cook at all.
NoSquirrels he has an office manager at work who sorts out his travel, but otherwise he manages his own diary so I know he's capable of doing it. However, I've often had to step in and fill in his business expense claims & scan receipts, as they can run into the thousands of £££s before he'd do them. Other than the car, I do all his personal financial admin re. ISAs, pensions, insurance etc as much as I can although things fall down when he needs to take action, e.g. he has no life insurance at the moment because he didn't call to request his medical form from the GP in time and the quote ran out. There's only so much I can do.
God, the more I write the worse he sounds. Good things are - he loves his children dearly, and I know that he loves me, although sadly not enough to change his behaviour, unfortunately.
And in fairness, the one task he does cover is all kids' birthday party duties as I can't bear them. However, I've ended up being responsible for making sure we have presents, cards & wrapping paper stocked in advance as he doesn't remember until it's time to leave. It's part laziness, part chronic disorganisation.
Graphista I agree with everything you're saying, I've just been trying for years to find a solution that means that my DCs don't have their family torn apart. I am taking it very seriously but I'm not quite there yet.
For a few years we had a fantastic nanny which I think helped to paper over the cracks as she covered up a lot of his deficiencies by being organised and proactive. But now that both DCs are in school it's just the two of us so it's crystal clear just how unbalanced our individual contributions are. He comes from a family where men aren't expected to lift a finger so that's no doubt where a lot of this comes from - his mother thinks it's amazing that he can cook and is involved in childcare at all and congratulates him often.