NBC:
WE REPORT, SO YOU DON’T HAVE TO THINK.
Isn’t the difference between an “informant” and a “spy” just a matter of perspective?
One would never say “We had a spy in their campaign.”
Instead, one would say, “We had an informant on the inside.”
Literally the same exact thing.
If my competition sent someone to come work for me and inform on my activities to them I would refer to that person as a “spy”, not an informant.