It depends on whether the P1us you have logged is legitimite P1us, ie it has been logged as the result of a succesful flight test (test for the issue or renewal of a license or rating, NOT monthly club checkouts, circuit checks etc) in which case it is legitimitely in the P1 column of your log book and can be used to satisfy the requirements.
minus273, the US equivalent of this is that you just call a succesful check ride P1 don't you ?
Your comment 'You are either PIC or you are not, if you have an instructor by your side etc etc .......' - now not to be rude as I try not to be - shows that you do not know your FARs. Somebody with a Private Pilot certificate receiving training for an Instrument ticket may quite legitimitely log the instruction received as P1 so long as they are the sole manipulator of the controls, ie they don't f*** up to the point where the instructor has to bail them out.