Sounds like **** to m
Sounds quite straight forward to me, your wife has debt and if you become a joint account holder you are responsible for the debt they are simply looking after your credit rating.
It sounds to me as if you are attempting to use your lump sum as show money and your wife's salary as history for a future mortgage or loan application...
If you have a Polish wife and your British and have a permanent address in Poland, I find it bizarre banks are not bending over backwards to open an account for you.
I don't see what there problem is with there not being a big enough income in the current account.
MarkC the reason is you are trying to get credit/credit cards and your wife has debt. Simple my friend.