Unless he will agree to nullify the agreement (it only needs to be torn up) then the only way of getting rid of it would be by a court application which he may want to oppose. It could be an expensive and risky exercise with very little reward. At the moment, there is an agreement which may not be enforceable because you signed it under pressure/duress .
What doesn’t help with that argument is the fact that you did take legal advice and then signed it.
Unless he will agree to rip it up and if you don’t want to go to court, my suggestion would be to get a different solicitor to write to the X saying that they have seen the agreement and been asked to advise on it and that in their opinion, it was entered under duress and because it is covering up a breach of contract, it’s not enforceable anyway and that if he feels differently, he should make an application to court to have the efficacy of the agreement determined by a judge.
The general principle is that the courts will not enforce an illegal agreement. It’s debatable whether this is illegal because it’s just covering up a breach of contract. However if the solicitor were to allege that in his opinion it’s bordering on fraud and hence, it’s not possible to enforce an agreement covering up fraud, you may find the ex to be more reluctant to push it.
You can always say that unless he will agree to rip the agreement up, you will make the application to court (you don’t have to go ahead with it) to have the matter determined by the judge and then, the breach of contract is likely to come out if the other party are called as witnesses!
A solicitor will know how to couch the letter for you.it will have more weight coming from a solicitor than if it comes from you.
Can I clarify anything for you?
Please rate the service positive. It’s an important part of the process by which experts get paid.
I can still clarify things for you.