They can take any refund that your spouse would receive whether you file jointly or separately. The injured spouse form would not be of any benefit since you would have no independent tax refund of your own to protect since you had no taxable income of your own and would not have received any refund if you filed separately.
If you itemize and claim the mortgage interest then that can only be done on a joint return since you have an obligation to pay it since your name is on the deed. If filing separately that deduction would be lost to your spouse since he is not on the deed and you would not benefit from it.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
