Pardon former copper and witness around May 1st (6,2)
I believe the answer is:
excuse me
'pardon' is the definition.
(I know that pardon can be written as excuse me)
'former copper and witness around may 1st' is the wordplay.
I cannot really see how this works, but
'former' could be 'ex' (prefix meaning former or onetime) and 'ex' is located in the answer.
'copper' could be 'cu' (chemical symbol) and 'cu' is present in the answer.
'may 1st' could be 'm' (1st letter of 'may') and 'm' is located in the answer.
'witness' could be 'see' (synonyms) and 'see' is present 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 excuse me that I've seen before include "What one's clumsy partner might say" , "Come again" , "interrupting dance" , "said to attract attention" , "Steps" .)