at the very worst
At or of the worst, least favorable, or least desirable outcome possible. Often indicates a belief or insinuation that such an outcome will not be disastrous or that a more positive outcome is as likely. You should ask him out on a date. At the very worst, he might say no, which really isn't that big a deal! He thought at the very worst he'd get detention for bringing alcohol to school; he wasn't expecting them to expel him.