CPL/MEIR can be done for less than £20k if you do your homework.
However, if you are starting from scratch, you will need a PPL, ATPL groundschool, 100 hours of P1 (often refered to as 'hour building') and an MCC.
Very approximately,
PPL~8K
100 hours P1~8K
Groundschool~3k
MCC~3K
Exams/test fees/aircraft hire for test~5K
This brings you to around £45K - £50K from start to finish as an absolute minimum. This excludes resits, extra training, travel, accomodation, medical etc etc...
This is why people are doubting your headline figure of £20K. I always tell my students not to expect any change out of 50 grand.