Simply saying if you join an Integrated ATPL course you will "normaly" not requiere a PPL, i say normaly because i don't know of any schools that do so or during my flight time heard of anyone that mentioned the need to do have one before joining. What they do requiere like for instance Oxford, FTE etc. is that you pass their admissions tests, which will test you to see if you have the capability on maths, physics, interview etc.
Now a Modular ATPL training, since it involves a lot more of self study than attending to class on an Integrated it would requiere you a PPL before start. Normaly no admission tests, simply the license and the medical, then off you go.
Most of the people today do a Modular course because of the price difference.
Hope it helps and good luck!
