Poles excluded from last visa to European country (6)
I believe the answer is:
latvia
'to european country' is the definition.
(country in Europe)
'poles excluded from last visa' is the wordplay.
'poles' becomes 'SS' (two S's - as in the South Pole).
'excluded from' indicates named letters should be taken away.
'last'+'visa'='lastvisa'
'lastvisa' with 'ss' taken out is 'LATVIA'.
(Other definitions for latvia that I've seen before include "European republic, capital Riga" , "Riga's country" , "Northeast European country" , "Country in northern Europe" , "Baltic state, capital Riga." .)