Many thanks for your patience. You are still potentially able to pursue this under employment laws by arguing this was an unfair dismissal, both for the reasons behind the decision and also procedurally. As you have more than 2 years’ service you are protected against unfair dismissal so to legally and fairly dismiss you the employer must show that there was a fair reason for doing so and also follow a fair procedure. So you could challenge the reasons they used to dismiss and also the procedure leading up to the dismissal, such as you being followed and any other concerns you have.
In terms of separate action, that would be quite difficult. Legally there is nothing stopping someone from following someone else and this only becomes an issue if it is done regularly or if the person has expressed a wish not to be followed. In these cases it may become harassment but generally it is legal – after all you have personal investigators following individuals and even one person may follow another without them knowing – it is not illegal.
Recording you is also not directly illegal but it can amount to a breach of trust and confidence on the employer’s part and also if they kept a recording of this it can also be a data protection breach. You cannot take it further unless you have suffered losses as a result, but in this case you have not, the dismissal is a separate matter so there is no possibility of a claim for these things. Therefore, an unfair dismissal claim and a claim for detrimental treatment/dismissal due to making a protected disclosure is still your best bet.
This is your basic legal position. I have more detailed advice for you in terms of the steps you need to follow to take this further, which I wish to discuss so please take a second to leave a positive rating for the service so far (by selecting 3, 4 or 5 stars) and I can continue with that and answer any further questions you may have. Don’t worry, there is no extra cost and leaving a rating will not close the question and we can continue this discussion. Thank you