Pretentious - did you hear? - twinning this Israeli port with Luton? (5)
I believe the answer is:
haifa
'pretentious did you hear? twinning this israeli port with luton?' is the definition.
'haifa' can be an answer for 'israeli port' (I've seen this before). I'm not sure about the remainder of the definition.
This is the entire clue.
Can you help me to learn more?
(Other definitions for haifa that I've seen before include "Middle East city" , "Seaside city" , "Seaport in Israel" , "Port of N. Israel" , "Major Israeli port" .)