A couple take out a joint mortgage. Can a second charge be taken out on the property without joint consent?

The husband built up a huge debt, which the wife knew nothing about. The first she knows about it is when she opens a letter from the company who has taken out a second charge on her jointly owned property. Does the wife have any options financially? (She no longer wants to be married to him but has two very young children by him. The husband built up an intricate web of lies by which to deceive her and they now have no money. Her only security now has two legal charges on it). Any advice will be gratefully received.