To be absolutely clear you do NOT need 100 hours P1 to start your CPL training.
You need a TOTAL time of 150 hours to start the CPL training.
You DO however need 100 hours P1 to have your CPL issued after your training and a successful flight test. You can include the any PICUS time you have towards the 100 hours In command. (This will include any successful flight tests you've completed at the time you apply for your CPL licence)