I think my point is that you can be an ex-partner but not an ex-wife or husband until you are formally divorced and a decree nisi is issued. When a divorce is settled, then both parties have arguable rights including shares in any property, monies and other assets. As I understand it, a married couple remain in principle enttled to each others possessions including property irrespective of the fact that they are no longer partners until the marriage is formally dissolved. I believe it is irrelevant whose name is on the various documents – that is after all the idea of a marriage?
Legally, I do not believe the husband could easily evict his wife from the property and I think the two regs I have posted above are your best starting point.
Just as importantly, I suggest you advise your customer to obtain advice from a solicitor spercialising in matrimonial law.