How far are you being done on your Aviation Diploma? 1/2 year? 1 year? 2 years?
If you're really close to finish your diploma, why not finish it off? It's good for yourself, knowledge, perhaps, maybe future career.
However, if you've just started it, why not go for the CPP.
Just my opinion, if you can get in to CPP, who cares about your diploma anymore?
What do you mean by (2nd chance)???
Good Luck!!
SonicCat