if (one's) life depended on it

if (one's) life depended on it

Under any circumstances; no matter what. (Used almost exclusively with a negative statement regarding something that one couldn't or wouldn't do.) No way am I going to karaoke night. I couldn't sing if my life depended on it! No thanks, I wouldn't see that film if my life depended on it.
See also: depend, if, life, on
Farlex Dictionary of Idioms.
See also:
  • sossled
  • sing along
  • sing down
  • sing out
  • pratt
  • prat
  • hang on for dear life
  • hold on for dear life
  • sing together
  • sing up