a blind bit of (something)
The smallest or any amount of something. (Usually used in negative constructions.) It doesn't make a blind bit of difference to me whether you do it now or this weekend—just get it done! I've been trying to show her I fancy her, but she hasn't taken a blind bit of notice.
a blind bit of —
the smallest bit of—; no — at all. informal 1995 Patrick McCabe The Dead School Not that it made a blind bit of difference what they thought, considering the way their lives were about to go.