1. You and boss have fraught relationship.
2. During lockdown, she makes you attend a face to face meeting with her and HR chap.
3. Prior to the meeting, she refuses to tell you what meeting is about but says it's not a formal HR process. HR chap also refuses to tell you.
4. You go in and secretly record the whole thing because you fear this is an ambush for a sacking or similar.
5. You are basically told off for very minor things that, to you, seem blown out of proportion.
6. She does you over in year end appraisal (based on the overblown things, although this was not a formal HR process). This in turn affects your potential promotion, salary, bonus, etc...
7. You formally complain.
8. You now know beyond any doubt and have proof that these spurious reasons are made up.
When the grievance is heard internally, you have to steer clear of the existence of the recording, right? Google seems to say the recording might be admissible in an employment tribunal but would constitute misconduct (albeit maybe not gross) from an employer perspective?