this discussion has gone off on all sorts of interesting tangents, but then the relationship between love and money is a pretty big subjet!
NotEqual, just picking up on a detail you gave. You say your dh brings in £5,000 per month after tax. £500 goes on your mortgage and £1000 approx on bills. He gives you £350. So that leaves about £3,150 of his earnings plus your earnings. So if he is unaware you have run up a credit card bill and he is suddenly told there's an extra £2,000 owing, that's quite a chunk of money out of your joint monthly income. I know you say there is a lot of money in savings accounts, but does your dh try to pay all bills, including his own credit card bills, out of your monthly income?
You say he is prudent. If he has a strict policy of living on the monthly income, then a sudden need to pay out £2,000 in one month would represent a big dent. I know it wouldn't leave you destitute, but it would be noticed.
Living off the monthly income and leaving the savings untouched could be a really big deal with him? If so, then your credit card bills are challenging this. To you he is blowing this occasional debt out of all proportion but to him, it's a big threat that undermines his trust in you.
I am playing devil's advocate. If sides are to be taken, I am more on your side than his as I agree you have much too little financial power.
I get the impression he really does keep you in the dark about the finer points of your family financies. That is wrong IMO if you see him spending far more money on himself than you are 'allowed' to spend on yourself. I think you really must force him to talk to you more, about monthly income, savings, plans for the future and you must tell him your own views in a non confrontational way.
If he is as prudent with money as you say, then it can't be part of his plan to pay needless interest to your credit card company. So what is really going on there?
Also, you keep saying you really are comfortably off and he can afford to give you more. Are you totally 100% sure this is the case? Have you read his recent bank and credit card statements?
You say that your dh pays his credit card bills monthly. I am not very au fait with the way credit cards work, but really, if he can do this, why does he need them in the first place? I apologise as this may be a really naive question - but if you can manage so well, why not just do away with credit cards altogether?