Hi,
how long have you been looking for a job? Where? And what kind of jobs have you been looking for?
I think you'll find that the general job situation is not particularily flash in the UK at the moment. And probably hasn't been for some time. Have you tried to volunteer in a Physio Clinic/ School/ Child Development Service?

In my opinion - I would not employ a fully qualified and registered Physio as Physio Assistant. And as in that job you only observe others or engage in delegated tasks, I do not believe it will further your chances as a Physio.

Just keep on trying and maybe stay away from the major cities where competition for jobs will be intense. Apply for jobs as a basic grade Physio that include clinical rotations and in-house IST, such as band 5.

Good luck!

Fyzzio