Sack poor writers in Bow for speaking out (3)

I haven't cracked this one yet — but the brilliant team at Times for the Times have:

Poor writers are HACKS which if you are a Cockney becomes ACKS, and if you further say it out loud, becomes our answer. I am not sure I have seen a homophone and a Cockney device used on the same word, so it may be something of a rare bird.