Time to demand church to form working group (4,5)
I believe the answer is:
task force
'working group' is the definition.
(I've seen this before)
'time to demand church' is the wordplay.
'time' becomes 't' (abbreviation).
'to demand' becomes 'askfor' (I've seen this before).
'church' becomes 'CE' (abbreviation for Church of England).
't'+'askfor'+'ce'='TASK-FORCE'
'to form' is the link.
(Other definitions for task force that I've seen before include "Group assembled for a particular undertaking" , "Temporary group to do a job" , "Single-purpose group" , "subcommittee" , "special unit" .)