Be last to appear on the programme – and pay for it (4,3,4)
I believe the answer is:
foot the bill
'be last to appear' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'the programme and pay for it' is the wordplay.
'the programme' becomes 'bill' (bill is a kind of programme).
'and' means one lot of letters go next to another (I've seen this in other clues).
'pay for' becomes 'foot' (as in to foot the bill).
'it' becomes 'the' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'foot'+'the'='footthe'
'bill' after 'footthe' is 'FOOT THE BILL'.
'on' is the link.
Can you help me to learn more?
(Other definitions for foot the bill that I've seen before include "what the not so popular music-hall entertainer must do?" , "Settle" , "Pay up" .)