Can merge-request be merged - custom pre-flight check

To enforce some policies when a merge request is merged i added a service side update hook - which is only executed when merging against develop.

This works as it should - but the problem is you only get the feedback after you accept the merge request.

What we want is some kind of preflight check - this MR can be merged. (Like gitlab itself does when it checks if the MR does’nt produce a conflict.

Is there any way to hook into this system?