Party divided over shifting stall, can’t believe it! (4,5)
I believe the answer is:
tall story
But I can't explain it at all! Could you help me understand?
(Other definitions for tall story that I've seen before include "Distortion of the truth" , "Incredible account" , "suggesting Jack and the Beanstalk?" , "Unbelievable yarn" , "Fairy tale" .)