Plan support also arranged (8)
I believe the answer is:
proposal
'plan' is the definition.
(I've seen this before)
'support also arranged' is the wordplay.
'support' becomes 'prop' (prop up can mean to support).
'arranged' is an anagram indicator (letters rearranged).
'also' with letters rearranged gives 'osal'.
'prop'+'osal'='PROPOSAL'
(Other definitions for proposal that I've seen before include "union offer?" , "a match might be arranged?" , "Offer - suggestion" , "Offer (to get spliced?)" , "Suggestion put forward for consideration" .)