So is this all about your Dad having visitors? Or is there a bit about your sister-in-law being given your Dad's medical details without his consent.  I can recall being very upset that my mother refused to have my Dad back home when he was dying from lung cancer.  He wanted to be at home and I was going to help.  I was really annoyed at her.  Maybe you could get the nursing staff and GP to call a 'care planning' meeting at the surgery or at the house.. Relevant family members to be present including your Dad!! Get the subject of emotional health addressed and there you discuss the issue of visiting.  Your dad can state his wishes.  Your mother can state her views.  If necessary draw up a visiting rotary which is not too strenuous for your Dad.  Retired social worker here.

WThank  you. 

I don’t think I worded what I posted very well. My problem is that my mum seems to want to make certain decisions without consulting my dad. 

I’m extremely close to my dad and want to see him every day and I know he wants to see myself and his grandkids as much as possible just now because he told me. My dad is unaware that my mum and brother have said they want days with no visitors. I don’t want my dad to know this so have spoken with them to say I think the decision lies with my dad and whatever he wants is paramount to what anyone else wants.  

This morning he woke up and got dressed for the first time since being diagnosed a few days ago. He asked if anyone was coming over. I know my mum and brother need their space as well but when I’m there they could use the time to take a break. It’s like they’re afraid to leave me alone with him and I don’t know why. They won’t give a straight answer if I ask.

Obviously as time goes on and he goes further downhill he may not be in a position to make decisions for himself. I’ve never encountered cancer this closely before but is it not vitally important that the person who is suffering needs to feel in control of their life as much as they can be?