Many thanks for your patience, I am pleased to be able to continue assisting with your query now. First of all, I am sorry to hear about the issues you have experienced in your situation.
You could indeed argue that this is a data protection breach because it is personal data abut you, from which you can be identified, and which has been shared with ithers who did not have the tight to know about it. Telling others you have tested positive for Covid is in no way different to telling them you have tested positive for any other disease or condition and employers cannot do that in any other circumstances, so it will be the same with Covid. In addition, it will be treated as a breach of the implied term of trust and confidence which exists in every employment relationship.
If you wanted to take it further you can raise a formal grievance about it with the employer. You can get a detailed explanation of the grievance process here:
In summary, an employee is expected to submit their concerns in writing and send them to their line manager, or whoever is nominated as the person to send grievances to under an official workplace grievance policy.
The complaint should include details of what the grievance is about, any evidence that may exist which is relevant and also what the employee wants their employer to do about this issue.
Once the grievance has been submitted, the employer is expected to arrange a formal grievance hearing, inviting the employee to attend and discuss the nature of their complaint. The meeting is also as an opportunity to ask for further clarification or information, as required.
Following the meeting, the employer will take time to consider all the issues and evidence and then make a decision, communicating it to the employee. If the outcome is not to the complainant’s satisfaction, they can appeal and get a second opinion from a different person assigned by the employer to consider the appeal. Once the appeal is also completed, that brings to an end the formal grievance process and there is no option to escalate it further internally.