Trainee CSAs are working shifts on stations but only being paid 80% of the normal wages. 100% of CSA wages is hardly enough to live on in London - 80% is leaving new recruits really struggling financially.
This seems to be a case of management trying to get work done on the cheap, and exploiting the fact that newcomers often don't want to make a fuss.
Our unions should stick up for the principle that everyone should be paid the full rate for the job.