Competition to get church into expensive contract (12)
I believe the answer is:
steeplechase
'competition' is the definition.
(steeplechase is a kind of competition)
'church into expensive contract' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'into' means one lot of letters goes inside another.
'expensive' becomes 'steep' (I've seen this before).
'contract' becomes 'lease' (lease is a kind of contract).
'steep'+'lease'='steeplease'
'ch' going into 'steeplease' is 'STEEPLECHASE'.
'to get' acts as a link.
(Other definitions for steeplechase that I've seen before include "Type of horse race" , "Non-flat horse race" , "run?" , "Race over fences" , "Horse race with ditches and hedges" .)