The Guardian seized mail returned to politicians (10)
I believe the answer is:
parliament
'the' is the definition.
I can't judge whether this defines the answer.
'guardian seized mail returned to politicians' is the wordplay.
I cannot quite see how this works, but
an anagram of 'mail' is 'liam' which is present in the answer.
'guardian' could be 'parent' and 'parent' is found in the remaining letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for parliament that I've seen before include "Houses" , "Diet" , "Legislative assembly" , "UK legislature" , "The law is laid down here" .)