We have a work rota for late finishes at work, due to the workload having a late finish also means you spend all day doing the most unpleasant job (I hope this makes some sense I don't want to go into too much specific detail). The rota is compiled by members of the team in a rotational basis, it is not set at management level.
I am part-time along with another colleague (who we'll call A), between us we do the same hours as full time workers.
The rota has always worked out slightly unfair to me and A because where leave and sickness are harder to cover it tends to be pushed on to one of us. Most people have one bad day per week (so every 5 days) but ours tend to average out slightly more frequent than this. The issue has been discussed many times and I've basically been told I have to live with it as it's too difficult to make it entirely fair and it should even out over time. Generally we have this discussion every month because it fails to even out, it always works out ever so slightly worse for me and A. I think only 1 of these discussions has been minuted formally during a team meeting and I'm not sure how much of the discussion was recorded (will check next time I'm in).
This month things have got much, much worse. There are issues with short staffing, instead of everyone picking up some of the slack it's all been given to me and A. Between the 2 of us we are doing double what everyone else is, so averaging a bad day every 2 or 3 days instead of every 5. Normally the rota is signed off by everyone before it's made formal, I was on leave so I've not signed it off, A must have agreed to it.
When it was sent to me I replied by email that I wasn't willing to sign it off (I'm still currently on leave but had asked a colleague to send it through so I knew what my hours were). I was sent back a snippy email saying I should do it if I thought I could do a better job (this would mean working from home, unpaid, whilst on leave).
What now? I'm not sure I want to turn this into a formal complaint with all the hassle that would bring but I really can't rearrange my life to do double my fair share of the work. I am only asking for fairness, not any special treatment for being PT. I just don't know how to make other team members see this without creating a hideous atmosphere and loads of hassle for everyone.
Apologies for the essay, I can answer any questions if any of it isn't clear.