The School’s Change of Circumstances processes for PhD students are not covered by formal appeals processes. Accordingly, you will not be able to submit a formal appeal against the decision made under the School’s Change of Circumstances process.
As noted above, if your supervisors do not support your request, you should discuss this with your department in the first instance. You are also welcome to contact the PhD Academy for advice at this stage.
If the Research Degrees Sub-Committee Chair does not approve your application, you should carefully consider the rationale provided by the Chair as part of your outcome notification. These will often provide guidance which will help you to understand whether alternative adjustments may be more appropriate to your circumstances, or what you might need to do in order to submit a further Change of Circumstances request. (If your application was rejected due to a lack of evidence, the Chair’s feedback should outline the types of evidence they would need in order to approve your application.)