Unfortunately, you're in a tough position. I would recommend having your Realtor and Attorney light a fire and speed up approval period. Is this a short sale or foreclosure? If so, the bank (seller) may be taking time to determine penalties, amount owed, etc. That process can take up to 8 weeks or more. The only other thing would be if someone came in with a better offer than yours and are trying to irritate you out of the transaction. In that case, yes, there is a possibility to sue for specific performance. Make sure your ducks are in place (mortgage, down payment, etc.) and go after what you agreed to.