If your partner is about to lose his job, this should be disclosed to your Realtor. If you do not have a Realtor, then the Seller's, immediately. This happened to one of my clients, the Seller's were very understanding and returned the security deposit. Lenders sometimes do another credit check and other verification prior to closing. Until he has lost his job, you may not be able to cancel out of the contract. Discuss this in detail with your agent and have them guide you as what to do.
Keller Williams Crossroads, Madison, WI