New direction ?
Found some posts from 2017 about this item on another forum , initially attributed to Korpus Polski , but final post states :
"have just found in a book devoted to the Second Polish Corps that
KP stands for Kwatera Polowa and therefore this slip on would have been worn by the staff of general Wladyslaw Anders' Field Headquarters."
IWM has a page (unfortunately no photo) :
BADGE, COLLAR, POLISH, ARMY, KWATERA POLOWA, HEADQUARTERS
Physical description
A pair of green, wool collar tabs featuring
the letters K.P. embroidered in white.