Expel from party covering Northern Ireland (6)
I believe the answer is:
banish
'expel' is the definition.
(banishing is a kind of expelling)
'party covering northern ireland' is the wordplay.
'party' becomes 'bash' (bash is a kind of party).
'covering' is an insertion indicator.
'northern ireland' becomes 'ni'.
'bash' going around 'ni' is 'BANISH'.
'from' acts as a link.
(Other definitions for banish that I've seen before include "Send (someone) away" , "Expel from a community or group" , "Send away (as punishment)" , "Condemn to exile" , "Cast out, ostracize" .)