I think PP means even if he pleads guilty he may go to jail.
The reason for this is that he already has /will have one count of assault to his partner against him ( the common assault), now a second charge this time more serious against the same person is on the way. That makes it likely he will go to jail. It would look to the court that he assaulted her once and then a few days late returned and assaulted her again.
This really does need a solicitor he MUST get one ASAP.
A 'no comment'interview is rarely a good idea. I can not see a competent solicitor allowing him to make one. Remember the standard warning when anyone is arrested '' It may harm your defense , if you do not mention now something you later rely on in court'' That is why a 'no comment' statement is not a good idea. In reality they are more a plot in a film or TV drama than a sensible defense.