Urgent advice re compromise agreement?

[SQL]

Hi - if anyone has been thru' this would interested to know what is reasonable to ask for a rapid resolution?
I work in a field wher I get Xk basic & X bonus for perfomance against target, and have always met my annual target except last year when I didn't and had already started a grievance procedure for bullying against my manager who as done things that appear to have deliberately scupper my chances of achieving. I also have a flexible agreement which I beleve he was trying to get rid of. I am 50 and one of the few remaining employees on a final salary pension scheme, and teh only one with a term-time working arrangement. My salary is a reduced amount pro-rata for my flexible time (term time), but my target has never been reduced - ie is the same amount as others who work full time.So i have rasied a grievance, although they have been very slow. In the meantime, at my insistance i have been temporarily assigned to another manager.
However, I think my confidence in the compnay is such that I don't see a happy outcome, and that the result will be me leaving.
Any view on whether it is better for me to leave and pursue a contrcutive dismissal, or now ( what I would prefer) to suggest a compromise agreement?
If the latter, what level would pitch it so that accept and I avoid the trauma of a tribunal?
Andy advice gratefuly received!

On what basis would you be suggesting a compromise agreement? If you come to your employer and say you want to leave the only reason they have for agreeing to a compromise agreement (I assume you want them to pay you some additional money?) is if they are convinced you have a good case against them for something and are fully prepared to go to tribunal.

You only mention bullying really, and that a grievance is ongoing, so on that basis it would be incredibly difficult to bring a claim of constructive dismissal and you would probably be unlikely to win. This means your employer has no incentive to accept a compromise agreement. By asking for one yourself (rather than proceeding as if you are going to bring a claim and waiting for them to offer you one) you are indicating that you a) want to leave anyway and b) don't want to go to tribunal.

Yes I agree your targets should be pro rata, but unless they have been pro rata to date and your employer is suddenly increasing them, I can't see much of a claim for constructive dismissal there tbh.