the branch of the co-op bank I use is in a Britannia branch,due to the probs co-op is having,this local branch may be closed,does the post office take co-op payments?
Unless the system has changed you will need a special envelope supplied by your bank to deposit cheques. It's very unlikely your PO will have a stock of these
Your local Post Office should have an emergency supply of envelopes for you to make cheque deposits, though if you are going to do this on a regular basis it would be advisable for you to contact the Co-Op bank and ask them to send you your own supply. The only cheque deposit envelopes that the Post Office do not supply are Halifax ones.