What is wrong with these people?! If they (supervisors) worked in the private sector they would have been hauled in front of an employment tribunal for this behaviour!! Mine is no exception, I just make sure I warn prospective students, probably why he has had no new PhD students since I started he he!

Thank you so much for the usefull replies guys, some very helpful tips! Basically, my Boss is extremelly manipulative and will do/say pretty much anything to get you to do what he wants regardless of your best interests. Our lab is short of cash and so taking in more students will bring in extra money. I sent him a list of all the expts I need to do to in order to complete my thesis and it is huge! Hopefully he will now reconsider all these additional things without me having to refuse to take the students!

I am a final yr PhD student and my supervisor recently found out that I am planning to stay in science on do a post-doc. Since then, he has been making me do all kinds of random things that detract from finishing my thesis on time such as supervising undergrads for 12wk projects, training other PhD students from scratch etc. When I protest he tells me that he will have no problem recommending me for a job if I do these things he asks! Perhaps I'm over reacting but it does seem he is blackmailing me into doing these things because he knows I need to keep him on my side

My lab has been turning into a nightmare by the arrival of a post doc. When she started she appeared all meek and mild but as she was given more responsibility the power seemed to go to her head. She became extremely bossy, rude and arrogant. She tries to turn very small things into raging arguments to make us PhD students look like idiots in front of our supervisor. To make things worse she has taken to gossiping with my supervisor about us, telling half truths and in some instances making things up so that she will appear more favorable. I have discussed the problem with my supervisor but he just makes excuses for her or sides with her.
I'm don't know how to handle the situation, I'm getting to the point when I don't even want to come into the lab, surely this constitutes bullying?