Well this is going to change, (which is why I started this thread), and the onus will be based on the risk that an individual highway user poses to others. So in the case of a cyclist being on the kerbside of a motor vehicle, the driver is obliged to:
a) establish that the roadspace that they are going to move into is clear of cyclists/pedestrians
b) give priority to cyclists turning into and pedestrians crossing side roads.
In the case of cyclists, once motor vehicle drivers learn the priority rule (probably helped by awareness of a few high-profile prosecutions) a major cause of cyclist serious injuries and deaths will be at least reduced.