Surprisingly, UK calmed by this ineffectual person (4,4)
I believe the answer is:
lame duck
'ineffectual person' is the definition.
(I've seen this before)
'surprisingly uk calmed by' is the wordplay.
'surprisingly' is an anagram indicator (a surprising ordering of the letters).
'by' means one lot of letters go next to another.
'uk'+'calmed'='ukcalmed'
'ukcalmed' anagrammed gives 'LAME DUCK'.
'this' is the link.
(Other definitions for lame duck that I've seen before include "Useless person or thing" , "Failing company" , "Person with rapidly declining power" , "Inefficient or helpless person" , "Person in need of help - like injured eider?" .)