What are the consequences of not paying owed attorney fees ?

Yes that's a tough situation but it's a debt like any other and likely well documented. Attorneys have been known to charge interest, sue to collect, and turn unpaid bills over to collection agencies. Really the best thing you can do in a case like this is contact the attorney and explain the situation and see if some sort of accomodation can be worked. Many attorneys are sympathetic to their clients and will try to accomodate them as they really do not like suing a client who is suffering a hardship paying a bill.

This is a bill like any other. The lawyer put in a lot of time and bills to pay as well. How long would you work at your job if you weren't getting paid. The lawyer has every right to charge interest, pursue collections, and other legal avenues. Contact the lawyer immediately and offer regular monthly payments that you know you will be able to pay in full every single month. Also, see if family members can also help out. Owing family money is way better than owing it to a business that can come after you. If you had to put off doing your taxes, maybe resolve to have the refund go to the lawyer. Like any other business, lawyers want to make sure there's progress on getting the bill paid rather than deal with lots of promises or chasing disappearing clients.