hi Saskia123
am I understanding correctly - the solicitor said that they "had not had any instruction to continue" which means that your mum has not continued with setting up the POAs, which means that no POAs are in existence
if so, then no-one but your mum can deal with/manage her affairs
so if/when she is deemed to no longer have the capacity to manage her financial affairs, someone will have to apply for Deputyship - and I personally can't see her husband doing that - so will you? (I can't see that he will have grounds to object, and his financial history means you could object to an application he makes)
can you speak to your mum? would she go with you to set up the health & welfare POA?
I appreciate that you are angry that all your efforts at compromise and keeping your mum safe have been scuppered - though he has no POA either (but I suppose for h&w he is, as spouse, her next of kin) -galling!
at least he knows you are looking out for your mum and always will
best wishes