This is not really a legal question, but one of academic standards and it would never be decided on a legal level. That's as far as the legality issue goes.

However, there is a good chance that at least one side here is likely to be acting unethically or at least questionably, but this is outside of the realm of the legal.

1. Either your co-authors wish to publish a premature result and you are rightly unhappy that the work is not carried out to satisfaction.

2. Or you are unreasonably perfectionistic or perhaps even overpedantic and you wish to block your co-authors from publishing a perfectly acceptable result.

We are not able to judge that. Basically, from a purely formal academic integrity point of view, you can sabotage your fellow authors by blocking them from publication. Your contribution is such that they cannot remove you from the author list without violating a core contract of academic authorship. In other words, strictly spoken, you can - at least as concerns academic rules - prevent them from publishing. They can not circumvent that without breaking academic integrity.

That being said, if you would be sabotaging a publication without very good reason (as I say, we have no grounds to determine either way), this could be considered a violation if not of the letter of academic conduct, but of its spirit.

A supervisor of such a student scrupulous in matters of academic integrity would probably not force the issue on that paper and just cut their losses. However, they would be perfect in their right to cut off the student from any promising critical project in the future and might also bring the case to the academic misconduct case if they think the blocking was unreasonable. If indeed the prospective author would be found sabotaging the paper, this would not bode well for them; nobody likes to see their departments' PhD supervisions and/or research funding wasted. Of course, the OP might consider appealing to the academic integrity board on their own side to prevent publication of the paper without their authorship or consent. Alternatively, OP might contact the journal it was submitted to, but that is already an escalation beyond the institution, and probably should be only considered as next step.

Note in all of that that the judgement of what would constitute a reasonable result is highly subjective and thus there is a considerable grey area of what would constitute a reasonable refusal to publish vs. an act of sabotage. I repeat: we have not enough information to come to either assumption, but I wanted to make sure OP has the full picture.

It may therefore be a wiser decision to contemplate whether an appropriately moderate honest presentation of the - not so impressive - results would make a publication acceptable, rather than trying to block it in its entirety; after all, that's the result, honestly presented. Other scientists then know they do not need to walk down this path.

To be honest, none of the above is really satisfactory; the best of all outcomes would be to entreat your coauthors with a convincing case as to what work needs to be done to bring the paper up to the standard that one would like to see it in rather than go into confrontation. If the results are not as desired, what alternative experiments/simulations could be done to achieve that.

This is not really a legal question, but one of academic standards and it would never be decided on a legal level. That's as far as the legality issue goes.

However, there is a good chance that at least one side here is likely to be acting unethically or at least questionably, but this is outside of the realm of the legal.

1. Either your co-authors wish to publish a premature result and you are rightly unhappy that the work is not carried out to satisfaction.

2. Or you are unreasonably perfectionistic or perhaps even overpedantic and you wish to block your co-authors from publishing a perfectly acceptable result.

We are not able to judge that. Basically, from a purely formal academic integrity point of view, you can sabotage your fellow authors by blocking them from publication. Your contribution is such that they cannot remove you from the author list without violating a core contract of academic authorship. In other words, strictly spoken, you can - at least as concerns academic rules - prevent them from publishing. They can not circumvent that without breaking academic integrity.

That being said, if you would be sabotaging a publication without very good reason (as I say, we have no grounds to determine either way), this could be considered a violation if not of the letter of academic conduct, but of its spirit.

A supervisor of such a student who is scrupulous in matters of academic integrity (the supervisor) would probably not force the issue on that paper and just cut their losses. However, they would be perfect in their right to cut off the student from any promising critical project in the future and might also bring the case to the academic misconduct case if they think the blocking was unreasonable. If indeed the prospective author would be found sabotaging the paper, this would not bode well for them; nobody likes to see their departments' PhD supervisions and/or research funding wasted. Of course, the OP might consider appealing to the academic integrity board on their own side to prevent publication of the paper without their authorship or consent. Alternatively, OP might contact the journal it was submitted to, but that is already an escalation beyond the institution, and probably should be only considered as next step.

Note in all of that that the judgement of what would constitute a reasonable result is highly subjective and thus there is a considerable grey area of what would constitute a reasonable refusal to publish vs. an act of sabotage. I repeat: we have not enough information to come to either assumption, but I wanted to make sure OP has the full picture.

It may therefore be a wiser decision to contemplate whether an appropriately moderate honest presentation of the - not so impressive - results would make a publication acceptable, rather than trying to block it in its entirety; after all, that's the result, honestly presented. Other scientists then know they do not need to walk down this path.

To be honest, none of the above is really satisfactory; the best of all outcomes would be to entreat your coauthors with a convincing case as to what work needs to be done to bring the paper up to the standard that one would like to see it in rather than go into confrontation. If the results are not as desired, what alternative experiments/simulations could be done to achieve that.