I am in my second year of my PhD and my supervisor is not sure if I should continue. I have a masters and don't need another. Can I continue if I loose the support from my supervisor? Does the supervisor have to give a reason for kicking me out?

The question is ,that why does your supervisor is not sure that you can do your PhD? you should continue it,though it is very difficult but not impossibe.It is must that your supervisor should give you the reason for kicking you out,and secondly you should start searching for another supervisor too,no matter he/she(former supervisor) shows his/her willingness to continue with you.But dont take a quick decision at all.I am sure you ll find another one soon.

It is actually quite difficult for a supervisor to officially dismiss a student. Consult your student handbook where it should outline the procedures that will be followed in the case of a student not achieving the required standard. This usually takes the form of a number of official verbal and/or written warnings. It's not good for the university to have to let students go so you should be given every chance to make the grade. Good luck

The student handbook is not of much use- doesn't say anything about waht happens if the supervisors assesment is negative.

I probably should have written the 'research degrees handbook' (may have slightly different title in your institution) rather than the student handbook you are giving at registration telling you about GP surgeries and student accommodation etc! Somewhere there will be a protocol or set of rules and regulations about monitoring research student progress and topics like procedures for Mphil/PhD transfer etc. Ask your postgraduate office if you can't find this info yourself.

You should think about what you can realistically expect to gain from continuing if your supervisor thinks the answer is 'nothing'. Maybe you should ask him/her to explain what he/she means by their comment and go from there. Maybe it was a tactic to get you to work harder. But on the other hand, it wouldn't be worth continuing if you're not suitable.