I am in a nightmare situation. I have joint power of attorney with my brother - but he is telling lies and acting unreasonably. We even had a mediation meeting with our solicitor - but he lied in that meeting. It's impossible to have reasonable discussions about the very important decisions we are having to make (i.e. care home choice for my mum who has dementia) He loses his temper and shouts at me when he doesn't agree with what I'm saying. He has been violent with me in the past. I deeply regret not including a solicitor as another attorney / deputy. I foolishly hoped my brother had changed and that through the pain of what has happened to mum we would support each other through this. Can anyone please advise what I can do legally - I am duty bound to act in mums best interest - but how can I do so like this?