Fifty in a hundred sacked, English included, without warning (10)

'without warning' is the definition.
(thesaurus)

'fifty in a hundred sacked english included' is the wordplay.
I cannot quite understand how this works, but
'fifty' could be 'l' (Roman numeral) and 'l' is found in the answer.
'a' is present in the answer.
'english' could be 'e' (abbreviation) and 'e' is located in the answer.
an anagram of 'hundred' is 'unhrded' which is located in the left over letters.
No letters remain.
This may be the basis of clue (or it may be nonsense).