Support for Tory PM no longer (5)
I believe the answer is:
truss
'support' is the definition.
(type of architectural support)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for truss that I've seen before include "Wing beam of a plane" , "Type of support" , "Bind - structural framework" , "Tie up tightly; frame" , "Frame supporting roof" .)