PM to get the boot! (10)
I believe the answer is:
wellington
I believe this clue is a double definition.
'pm' is the first definition.
(Duke of Wellington, former prime minister)
'the boot' is the second definition.
(Wellington boots are a type of boot)
'to get' is the link.
(Other definitions for wellington that I've seen before include "City" , "way to serve beef tenderloin" , "Victor at Waterloo" , "Waterproof boot" , "Knee-length boot" .)