Responsibilities of PI to PhD student post PhD submission, but pre-viva I have recently submitted my PhD. However, my project requires about 5 months more work to be publishable. The standard time between submission and the viva defence in my lab is about 5-6 months. I had hoped to do this work, defend and finish the paper over the next 5 months. I am not being paid as officially my PhD is over, but I want to see the project out to the end, both because I have worked on it for 4 years and I need a paper for career progression.

However, my PI and I have never worked well together, and now a post-doc who was originally asked to help out with my project seems to be preparing to take over. I have a meeting soon to clarify everything, and I'm determined to fight for this project and paper but am unsure if I may be asking/expecting too much. I'd really appreciate some help.


Does my PI have any obligations to help me in the period post-PhD submission but pre-viva? My contract is officially over, so can they refuse to let me enter the lab to do wrapping-up experiments, even one that would really help me pass my viva?
Can my PI take the project off me and give it to someone else if I don't finish it within the dates of my PhD? This would effectively end my academic career. (Everyone else graduating from our lab was given short-term postdoc extensions to finish up, so no-one in my lab has ever finished a paper in the time of their PhDs)
This answer is a bit blind as some information needed to give a more complete answer is missing. I'll try to give some guidance, but it is probably incomplete. 

You say that you haven't gotten along well with your advisor. You don't say why. There could be a lot of reasons, but if you have, through your own actions, given the advisor reason to question your commitment or ability to finish, then you may not get very far here. It is impossible to say what is "owed" in such a situation. 

You say you want to "fight for this project...", but I'd suggest that you change that approach a bit and stress why and how you are the best person to complete the work and how you guarantee that you can and will do it. Funding is a separate issue and, again, it is impossible to say what is "owed" here. 

Depending on the nature of the work, it may be completely reasonable for the professor to pass it on to someone else since you are no longer involved. In a lab situation, students very seldom "own" the research thread and that thread may be so important to complete that personalities matter less than the work itself - childhood cancer, say. 

Technically, your advisor owes you what was in the contract. Morally it may be more, but there isn't really enough information to judge it externally. 

On the other hand, an attempt to deny you your degree or prevent you from publishing your results or impeding your career would be unjust. 

If you want to stay with the project, however, convince your advisor that you can and will be the best person to do it. Any other approach is likely to fail.