Maybe management have been looking into what happened last time. Strike breakers sneaking in via obscure routes, calling in sick, panic leave requests, frantic scrutiny of duty roster hoping that it's a day off, any office numpty and/or manager with anything close to a validation anywhere being used to fill a seat.
It can come as no surprise that anyone showing competence in union activities can be promoted "on side", placing them in a tricky personal position.
Withdrawing goodwill or some other pathetic wishy-washy proposal is nothing, absolutely nothing!
I'll make my mind up when I've been briefed on all the facts by my union representative, and not before. Anybody else out there got "unauthorised absence" on their personal file......that is the measure of commitment you may be asked to make?