Motion in favour of standing (11)
I believe the answer is:
proposition
'motion' is the definition.
(thesaurus)
'in favour of standing' is the wordplay.
'in favour of' becomes 'pro' (being pro a particular cause).
'standing' becomes 'position' (standing can mean one's position or status).
'pro'+'position'='PROPOSITION'
(Other definitions for proposition that I've seen before include "Statement expressing a judgement or opinion" , "selection" , "Suggestion put forward" , "Premise - suggestion" , "Manifesto, plan" .)