Party — our group — beginning to resist payment for union (5)
I believe the answer is:
dower
'payment for union' is the definition.
I can't tell whether this defines the answer.
'party our group beginning to resist' is the wordplay.
'party' becomes 'do' (do can informally mean a party).
'our group' becomes 'we' (we or us).
'beginning to' indicates taking the first letters.
The initial letter of 'resist' is 'r'.
'do'+'we'+'r'='DOWER'
Can you help me to learn more?
(Other definitions for dower that I've seen before include "Sort of house" , "funding for Remainer" , "widow's allowance" .)