As far as I know, if you lost your job because you would not comply and that was the reason for your unfair dismissal, then you could you ask the Tribunal to take the recording into account or (if they refused to allow it to be admitted) you could make the transcript part of your Witness Statement. Having been recently involved with this process, it appears many applicants to the Employment Tribunals have recordings of their bosses (either over the telephone or at a meeting) which are often accepted. Furthermore, if your bosses have already made a Witness Statement to the contrary, then such tape recorded evidence often force the company to settle out of Court. Good Luck!!