Far-fetched tale by a six-foot, headstrong British pollie (4,5)
I believe the answer is:
tall story
'a six-foot headstrong british pollie' is the definition.
I know nothing about this answer so I can't tell whether this works.
'far-fetched tale by' is the wordplay.
'far-fetched' becomes 'tall' (I've seen this in another clue).
'tale' becomes 'story' (synonyms).
'by' says to put letters next to each other.
'tall'+'story'='TALL STORY'
Can you help me to learn more?
(Other definitions for tall story that I've seen before include "suggesting Jack and the Beanstalk?" , "Distortion of the truth" , "Incredible account" , "Fiction" , "romance?" .)