My supervisor won't accept that I won't stay in the lab for a PhD I have recently graduated a M.Sc. I have agreed with my supervisor that I will complete the work required in order to make my project publishable (we have agreed that this does not entail any additional analysis, only revisions of the manuscript, polishing some figures etc.) and another small project.
Despite the fact that I have made it clear to my supervisor that I am not interested in any further projects, he keeps offering my to stay in the lab for various projects.
Last week I have informed my supervisor that I have decided to take up a job unrelated to the lab.
The day after I received from him a text message offering me to stay in the lab and work on extension of my project in collaboration with another PI
I replied to him that I thank him for the offer but I that I prefer the job I have taken for personal reasons.
Today I have received an email from our collaborator, most probably written at the behest of my supervisor offering me a joint position with him and my supervisor on some expansion of my masters' project.

While this offer is legitimate in itself, I find it disturbing that my supervisor won't respect my will not do any further work with him.
I have to emphasize that what I have described above was just the latest in a long series of such attempts to persuade me to stay. Typically I say something along the line of "I don't want to stay in the lab because I won't to focus on X (X being some topic/method outside our group's speciality)" to which my supervisor will reply by either trying to persuade me that focusing on X is a bad idea or how can stay with him and still do X.

I also think I have good reasons not to want further work with my supervisor. Namely:


Our areas of interest are fairly different. Based on my experience during my masters' I don't think my supervisor has neither the will nor the required background to guide me in the approaches and methods I am interested in and is unlikely to to allow me to pursue these directions on my own.
We appear to have differences in our basic approach to what constitutes a good scientific work.
We do not have a good inter-personal communication which means that our differences leads to a constant conflict between us.
All of the above causes me considerable emotional distress. In fact, I feel that I have extended as much energy during my masters' on dealing with these emotional issues then on tackling the scientific problem at hand.
Since I know that other students of my supervisor have a much better communication with him, and since I had a very good experience with another PI I am working with, I think that problem doesn't lie squarely with neither of us.


I have started attending psychological consultation a few months ago and am trying to work out my emotions from my side, but I do not think staying in an environment that causes me this kind of distress is a good idea.

My goal is to find a way to convey to my supervisor the message that I am not willing to accept any more offers of this kind from him. I do not want to discuss my reasons with him because he will again attempt to persuade me why I'm wrong, and I definitely don't want to discuss my emotional issue with him.

Any advice on how to do that will be most appreciated.
"I am happy to polish the paper for publication as agreed; however, unfortunately, I cannot accept your generous offer. I have already accepted the other job and committed to it." - repeat and rinse. You agreed to the publication, which is fair enough. It is not your job to satisfy your supervisor's wishes outside of that. 

You are perfectly entitled to choose your future. Don't feel bad about that. You have your reasons to leave. Trust your gut feeling and accept you won't change your opinion. Once you accept that you won't change your opinion, it will be easier for you also radiate to your (former) supervisor that you won't change it.

Do not budge. Repeat your formulation. Only when they realise that you are not going to change your tune, they will relent.