OK, so I made a total arse of myself by posting this on the wrong thread, so have c&p'd it here.
The "she" is because I was answering someone on what I thought was this thread.

i am concerned that she cant manage of £50 a week for bits and bobs. I would love that to spend on whatever took my fancy. It seems to me that she needs help with her shopping addiction (and it is an addiction) and deal with why she needs to shop to make herself feel good, I am thinking in particular of her need to see her childrens happy faces when she has bought them something new. Also, it needs to address her need to be accepted by people who frankly dont matter. i am getting from her posts that her children probably rarely wear the same outfit twice at baby groups (happy to be corrected but that is the vibe), and is so bothered by snotty nosed bitches comments about "crap clothes".
I can see why her DH is concerned about having a joint account if she is, by her own admission, a spender and crap with money. But by being an officious arsehole he is actually making the problem worse because every time he tells her she is shit and refuses to discuss it, she feels worse and so goes out and buys something to make herself feel better.
I think that the cries of abuse regarding finances are a bit off, as I say, because she has admitted she would spend spend spend and you cant do that if you have a mortgage and bills to pay. So he may well be the only thing keeping them afloat. BUT.......he is being nasty about it and by refusing to pull his weight in the house and by lying about his "me" time, I would say that he is actually the one destroying the marriage.
I think his main problem isnt money but the fact that he wants the OP to STFU and do what he wants, and as she is now questioning it, he is threatening her with ending the marriage in order to get her to back off.
I dont think Relate would work for them as I get the feeling he would manipulate the situation and make her feel worse. But she definitely needs counselling to help with her issues and then she may be in a stronger position to either insist on a change in the status quo, or start afresh on her own.