Oh dear.... a plain PPL cannot fly in sub-VMC conditions, as a PIC, under any circumstances whatsoever.
Only correct in so far as it applies to a UK issued PPL.
I don't mean to make an issue of that, as obviously that's correct GAW's case.
But it's important to understand that that is not the case of other PPL's issued by other states, which don't attach a similar condition to their licences. Otherwise GAW will get totally confused when they look at other countries and see that they attempt to use SVFR to allow flight in sub VFR conditions.
dp