Uses long needles to reverse the Cockney pen and ink (5)
I believe the answer is:
knits
'uses long needles' is the definition.
The answer and definition can be both to do with contact as well as being verbs in their -s form.
Maybe there's a link between them I don't understand?
'reverse the cockney pen and ink' is the wordplay.
'reverse' says the letters should be written backwards.
'the cockney pen' becomes 'st' (I can't explain this - if you can you should give a lot more credence to this answer).
'and' is a charade indicator (letters next to each other).
'st'+'ink'='stink'
'stink' in reverse letter order is 'KNITS'.
'to' is the link.
Can you help me to learn more?
(Other definitions for knits that I've seen before include "Purses" , "Stitches" , "Unites" , "Works with needles and wool" .)