not have an earthly chance

not have an earthly chance

To have no possible or feasible chance of doing or accomplishing something. Primarily heard in UK. He doesn't have an earthly chance of winning, but I'm voting for him nonetheless. I knew I wouldn't have an earthly chance of getting that promotion if I didn't make myself stand out in the company more.
See also: chance, earthly, have, not
Farlex Dictionary of Idioms.

not have an earthly chance

Also, stand no earthly chance. Have no chance whatever, as in She doesn't have an earthly chance of getting into medical school, or Bill stands no earthly chance of winning the lottery. The use of no earthly in the sense of "no conceivable" dates from the mid-1700s.
See also: chance, earthly, have, not
The American Heritage® Dictionary of Idioms by Christine Ammer.

not (have) an ˈearthly (chance)

(British English, informal) (have) no chance at all: You haven’t an earthly chance of beating her at tennis — she is one of the best players in the country. ‘Any chance of getting a ticket for the concert?’ ‘Not an earthly, I’m afraid.’
See also: earthly, not
Farlex Partner Idioms Dictionary
See also:
  • not an earthly
  • not stand an earthly
  • not stand an earthly chance
  • lose out on (something)
  • lose out
  • lose out on
  • miss out
  • miss out on
  • miss out on (something)
  • on the chance