Many thanks for your patience, it is appreciated. I am now pleased to be able to provide further assistance with your query. First of all, I am sorry to hear about the issues brought up by this. It must be a frustrating situation to be going through.
It is probably unlikely that you would have a case for constructive dismissal at this stage and you need to give the employer the opportunity to deal with this and to try and take appropriate action. Only if this clearly does not happen and there is no plausible explanation for it, basically allowing such behaviour to continue, will you potentially have a claim.
At this stage, you need to pursue this through a formal grievance directly with the employer and give them the chance to formally deal with it.
You can get a detailed explanation of the grievance process here:
https://www.acas.org.uk/grievance-procedure-step-by-step
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. That is when constructive dismissal may become more of a realistic option.