1
general::
In complete opposition, as in The two brothers were poles apart in nearly all their views. This expression alludes to the two extremities of the earth's axis, the North and South poles. [Early 1900s]
American Heritage Idioms
2
general::
Phrase(s): *poles apart
very different; far from coming to an agreement. (Alludes to the distance between the north and south poles. *Typically: be ~; become ~; grow ~.) • Mr. and Mrs. Jones don’t get along well. They are poles apart. • They’ll never sign the contract because they are poles apart.
McGrawhill's American Idioms And Phrasal Verbs