In defence of supply teaching agencies I have encountered huge differences between them but that does not mean excellent ones don't exist!
First of all I must address your concern regarding police checking. Having joined a supply agency many years ago, I know that one of the first forms I completed was police clearance followed by many other reference checks and health questionnaires. The agency staff treated me with great respect.
Although I understand that I am currently paid less than I would be working via the local education authority, Iam happy to teach (and let's face it, supply teaching short term is just teaching, raw and pure) wherever I can, whenever I can. I have found LEA staff discourteous and unhelpful and I know for a fact that many schools find the same. Therefore they use agencies. The agencies provide a much better service for less money than the LEA, I get to teach and we are all happy. Not only that but I receive training, resources and advice.
I would urge young teachers to strongly consider joining supply agencies (but find the right ones). They can be just the right stepping stone into your career that you need.
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