Special team’s request in English court overturned (4,5)
I believe the answer is:
task force
'special team's' is the definition.
(team set up for a particular task or mission)
'request in english court overturned' is the wordplay.
'request' becomes 'askfor' (synonyms).
'in' indicates putting letters inside.
'english' becomes 'e' (abbreviation).
'court' becomes 'ct'.
'overturned' says the letters should be written backwards.
'e'+'ct'='ect'
'ect' reversed gives 'tce'.
'askfor' going inside 'tce' is 'TASK-FORCE'.
(Other definitions for task force that I've seen before include "work party" , "working group" , "working party" , "Group organised for a specific purpose" , "Group with a mission" .)