John, Not true! Clinical Scientists are not required to be registered until July 2005 (current undergoing transitional period). After that date you cannot claim to be a Clinical Scientists unless you are registered as it is a protected title. You can still practice if you called yourself something else.
There is no requirement to be registered by law, but it would be against the law to claim to be clinical scientist or technologist if not registered. It would be down to individual employers if they employed unregistered staff. You can call yourself say a EBME Engineer and still able to practice within the law. This is the message (rightly or wrongly) being given to unregistered clinical scientists who do not register by July, you can't call yourself a Clinical Scientist but you may call yourself a Medical Physicist but still be doing the same role.
I would like to hear Jim's or HPC's view on this as this needs confirming of denying so we can end all this speculation.