I will participate in request, not against making a start (10)

'a start' is the definition.
(initiation is a kind of start)

'i will participate in request not against' is the wordplay.
I cannot quite understand how this works, but
'i' could be 'a' and 'a' is found in the answer.
'in' is found in the answer.
'request' could be 'o' and 'o' is found in the answer.
This explanation may well be incorrect...

'making' acts as a link.

Can you help me to learn more?