Disregard Mr. Italy, primarily shameless to leave to England (6)
I believe the answer is:
ignore
'disregard mr' is the definition.
'ignore' can be an answer for 'disregard' (synonyms). I'm not sure about the 'mr' bit.
'italy primarily shameless to leave to england' is the wordplay.
'italy' becomes 'i'.
'primarily shameless' becomes 'rong' (I can't explain this - if you can you should give a lot more credence to this answer).
'to leave' says the letters should be written backwards (I've seen 'left' mean this).
'to england' becomes 'e'.
'rong' back-to-front is 'gnor'.
'i'+'gnor'+'e'='IGNORE'
(Other definitions for ignore that I've seen before include "Dismiss" , "Region in which to snub" , "Discount" , "Pass over" , "Deliberately take no notice" .)