If the paycheck is still good(dated within 120 days of note date), they will likely not ask for a new one(Neither Fannie or Freddie require it, but some lenders have their own internal requirements). However, where you will run into issues is they are required, by both Fannie and Freddie, to pull a Verification of Employment within 10 days of the Note date. If that shows you are not currently employed, and you cannot qualify solely on your spouses income, the deal is dead. I've seen deals die the day before/morning of closing when we found the borrower wasn't employed any more.