Likely to happen (2,3,5)
I believe the answer is:
on the cards
'likely to happen' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for on the cards that I've seen before include "Quite possible (colloq.)" , "A merry Christmas is" , "to have a PAYE job?" , "place for 6 19 [SEASONALMESSAGES]" , "a fair certainty" .)