Another possibility is that you could have a seized rear brake slave cylinder. There have been several occurrences of this on M3W's and it seems that it is common on 4 wheelers that use the same set up. That is assuming your car is not "new". The parts to replace are listed in the Alternative Parts List here:
https://www.dropbox.com/s/o9sokmoxizjosmf/Updated%20list%2012%2016%20Aug%202019.pdf?dl=0 Not sure how available Leyland LDV 200 or Ford Transit parts are in the US but that is what they are from.
